阅读说明：本技术 一种七甲川羧基吲哚花菁染料及其制备方法和应用 (Heptamethine carboxyl indole cyanine dye and preparation method and application thereof ) 是由 吴爱国 蒋振奇 袁博 李娟� 于 2019-03-08 设计创作，主要内容包括：本申请公开了一种七甲川羧基吲哚花菁染料及其制备方法和应用,属于多甲川吲哚花菁染料及其制备领域。所述七甲川羧基吲哚花菁染料的结构式如式(I)所示：<Image he="202" wi="700" file="DDA0001989587930000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>该染料具有近红外光吸收和荧光显影性能,可用于探针助剂。所述染料的制备方法包括以下步骤：1)将含有2,3,3-三甲基-羧基吲哚衍生物和亲核取代化合物的原料在真空条件下升温反应,得到有机铵盐；2)将含有步骤1)中得到的有机铵盐和环烯衍生物的溶液在封闭条件下升温反应。该方法具有合成路线短、溶剂环境友好、工艺简单、避免贵金属催化、产率高以及纯度高等优点,且适用性强,可用于合成多种结构类型的产物。(The application discloses a heptamethine carboxyl indole cyanine dye, a preparation method and an application thereof, and belongs to the field of polymethine indole cyanine dyes and preparation thereof. The structural formula of the heptamethine carboxyl indole cyanine dye is shown as the formula (I): the dye has near infrared light absorption and fluorescence development performance and can be used as a probe auxiliary agent. The preparation method of the dye comprises the following steps: 1) mixing 2,3, 3-trimethyl-carboxyl indole derivative and nucleophilic extractionHeating the raw materials of the substituted compound under a vacuum condition for reaction to obtain organic ammonium salt; 2) heating the solution containing the organic ammonium salt and the cycloolefin derivative obtained in the step 1) to react under a closed condition. The method has the advantages of short synthetic route, environment-friendly solvent, simple process, avoidance of noble metal catalysis, high yield, high purity and the like, is high in applicability, and can be used for synthesizing products with various structural types.)

1. A heptamethine carboxyl indole cyanine dye is characterized in that the structural formula is shown as the formula (I):

wherein R is selected from R₁And R₂One of (1);

when R is R₁When R' is selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, a is selected from an integer more than 0 and less than or equal to 14, X is selected from fluorine,Chlorine, bromine, iodine or perchlorate, m ═ 1, p ═ 0, a is selected from ethylene, linear propylene or linear butylene; or

R' is selected from carboxylate or sulfonate, a is selected from an integer which is more than 0 and less than or equal to 14, Y is selected from hydrogen, sodium or potassium, m is 0, p is 1, A is selected from ethylene, linear propylene or linear butylene;

when R is R₂When R' is selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, b is selected from an integer of 0 to 7, X is selected from fluorine, chlorine, bromine, iodine or perchlorate, m is 1, p is 0, A is selected from ethylene, linear propylene or linear butylene; or

R "is selected from carboxylate or sulfonate, b is selected from an integer from 0 to 7, Y is selected from hydrogen, sodium or potassium, m ═ 0, p ═ 1, a is selected from ethylene, linear propylene or linear butylene.

2. The heptamethine carboxyindocyanine dye of claim 1, which has a structural formula represented by formula (I-1), formula (I-2), or formula (I-3):

。

3. heptamethine carboxyindocyanine dye according to claim 1, in which R in formula (I) is selected from R₁And R₂One of (1); wherein the content of the first and second substances,

when R is R₁When R' is selected from hydrogen, carboxyl or ester group, a is selected from 2, 4, 6 or 8, X is selected from bromine or iodine, m is 1, p is 0, A is selected from ethylene or linear propylene; or

R' is selected from carboxylate or sulfonate, a is selected from 3, 5, 7 or 9, Y is selected from sodium, m ═ 0, p ═ 1, a is selected from ethylene or linear propylene;

when R is R₂When R "is selected from hydrogen, carboxyl or ester group, b is selected from 0, 1, 3 or 5, X is selected from bromine or iodine, m ═ 1, p ═ 0, a is selected from ethylene or linear propylene; or

R "is selected from carboxylate or sulfonate, b is selected from 0, 1, 3 or 5, Y is selected from sodium, m ═ 0, p ═ 1, and a is selected from ethylene or linear propylene.

4. A process for the preparation of heptamethine carboxyindocyanine dyes as claimed in any one of claims 1 to 3, comprising the steps of:

1) reacting raw materials containing 2,3, 3-trimethyl-carboxyl indole derivatives and nucleophilic substitution compounds at 80-130 ℃ for 4-24 hours under a vacuum condition to obtain organic ammonium salt;

wherein, the structural formula of the 2,3, 3-trimethyl-carboxyl indole derivative is shown as the formula (III-1):

the nucleophilic substitution compound is selected from at least one compound with a structural formula shown as a formula (III-2), a formula (III-3) or a formula (III-4):

in the formula (III-2), R¹Selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, a is selected from an integer which is more than 0 and less than or equal to 14, and X is selected from fluorine, chlorine, bromine, iodine or perchlorate; in the formula (III-3), R²Is selected fromc is an integer from 1 to 13; in the formula (III-4), R³Selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, b is selected from an integer of 0 to 7, and X is selected from fluorine, chlorine, bromine, iodine or perchlorate;

the structural formula of the organic ammonium salt is shown as a formula (III-5), a formula (III-6) or a formula (III-7):

in the formula (III-5), R¹A and X are as defined in formula (III-2), and m is 1; in the formula (III-6), R^2'Selected from the group consisting of carboxylate and sulfonate, c being as defined in formula (III-3); in the formula (III-7), R³B and X are as defined in formula (III-4), and m is 1;

2) reacting the solution containing the organic ammonium salt and the cycloolefine derivative obtained in the step 1) for 8-48 hours at 50-80 ℃ under a closed condition to obtain the heptamethine carboxyl indole cyanine dye;

wherein the structural formula of the cycloalkene derivative is shown as a formula (III-8):

in the formula (III-8), A is selected from ethylene, linear propylene or linear butylene.

5. The method according to claim 4, wherein the structural formula of the cycloolefin derivative is represented by the formula (III-8-1), the formula (III-8-2) or the formula (III-8-3):

。

6. the method according to claim 4, wherein in step 1), the molar ratio of the 2,3, 3-trimethyl-carboxyindole derivative to the nucleophilic substitution compound is 1:1 to 1: 12;

preferably, in the step 1), the molar ratio of the 2,3, 3-trimethyl-carboxyl indole derivative to the nucleophilic substitution compound is 1: 1-1: 2;

more preferably, in step 1), the molar ratio of the 2,3, 3-trimethyl-carboxyindole derivative to the nucleophilic substitution compound is 1: 1.5;

preferably, in the step 1), the raw materials are reacted for 8-16 hours at the temperature of 100-120 ℃;

more preferably, in the step 1), the raw materials are reacted for 10 to 14 hours at the temperature of 110 to 120 ℃;

preferably, in the step 1), the raw materials are reacted under the pressure of 2-200 Pa.

7. The method according to claim 4, wherein in step 2), the molar ratio of the cycloalkene derivative to the organic ammonium salt is 1:2 to 1: 6;

preferably, in the step 2), the molar ratio of the cycloalkene derivative to the organic ammonium salt is 1: 2-1: 3;

more preferably, in step 2), the molar ratio of the cycloalkene derivative to the organic ammonium salt is 1: 2.5;

preferably, in the step 2), the solution is reacted for 10 to 30 hours at a temperature of between 60 and 80 ℃;

more preferably, in the step 2), the solution is reacted for 15-28 hours at 70-80 ℃.

8. The method as claimed in claim 4, wherein in the step 2), a precipitator is added after the reaction, the mixture is maintained at 1-10 ℃ for 12-48 hours and then is filtered by suction to obtain the heptamethine carboxyl indole cyanine dye;

preferably, in the step 2), a precipitator is added after the reaction, and the mixture is maintained at 4 ℃ for 24 hours and then is filtered by suction to obtain the heptamethine carboxyl indole cyanine dye;

preferably, the precipitant is selected from at least one of petroleum ether, diethyl ether, dimethyl ether, propyl ether and methyl ethyl ether;

preferably, in the step 2), the solvent in the solution is selected from at least one of water, methanol, ethanol, propanol, ethylene glycol, glycerol, butanol and butanediol;

more preferably, in step 2), the solvent in the solution is selected from at least one of methanol, ethanol and propanol.

9. A probe auxiliary agent comprising at least one of the heptamethine carboxyindocyanine dye of any one of claims 1 to 3, the heptamethine carboxyindocyanine dye produced by the method of any one of claims 4 to 8.

10. The probe assistant according to claim 9, wherein the heptamethine carboxyl indocyanine dye is used for preparing a near-infrared fluorescent probe;

preferably, the near-infrared fluorescent probe comprises a small molecule probe and a nano probe.

Technical Field

The application relates to a heptamethine carboxyl indole cyanine dye and a preparation method and application thereof, belonging to the field of polymethine indole cyanine dyes and preparation thereof.

Background

Indocyanine green in the heptamethine cyanine dye is the only near-infrared dye approved by the food and drug administration and capable of being used for clinical development photothermal therapy, and the derivative of the indocyanine green belongs to one of the heptamethine indocyanine dyes. The dye has a strong absorption effect in a near infrared region near 808nm, can be used as a complementary imaging technology of other medical diagnosis and treatment methods (such as MRI, PET, SPECT, ultrasonic echo scanning technology, radiography and tomography), can also be used as a photosensitizer for photothermal therapy, and has important research value and application value in life science and biomedical research.

The heptamethine indocyanine dye has a plurality of modifiable sites, and can greatly expand the combined use of the dye and micromolecular drugs and the like. Currently, only one of the indocyanine green (IR-820) is available on the market, and the purity is low (80%) and the price is high (1324 yuan/g). Meanwhile, the production and purification processes of different derivatives of the derivatives need to carry out a large amount of condition screening and consume a large amount of organic solvents, and most of the selected solvents are high-toxicity solvents, such as o-dichlorobenzene, toluene, benzene and the like. Therefore, there is a need in the art to develop a new method for preparing and purifying heptamethine carboxyl indole cyanine dye with low toxicity, which is suitable for industrialization, thereby realizing the preparation of the dye with high efficiency, low cost and low toxicity.

Disclosure of Invention

According to one aspect of the application, a heptamethine carboxyl indocyanine dye is provided, which has the performance of near infrared light absorption and fluorescence development.

The heptamethine carboxyl indole cyanine dye is characterized in that the structural formula is shown as the formula (I):

wherein R is selected from R₁And R₂One of (1);

when R is R₁When the compound is used, R' is selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amide group, sulfonic group, ester group, alkynyl or amino, a is selected from integers which are more than 0 and less than or equal to 14, X is selected from fluorine, chlorine, bromine, iodine or perchlorate, m is 1, p is 0, and A is selected from ethylene, linear propylene or linear butylene; or

R' is selected from carboxylate or sulfonate, a is selected from an integer which is more than 0 and less than or equal to 14, Y is selected from hydrogen, sodium or potassium, m is 0, p is 1, A is selected from ethylene, linear propylene or linear butylene;

when R is R₂When R' is selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, b is selected from an integer of 0 to 7, X is selected from fluorine, chlorine, bromine, iodine or perchlorate, m is 1, p is 0, A is selected from ethylene, linear propylene or linear butylene; or

R "is selected from carboxylate or sulfonate, b is selected from an integer from 0 to 7, Y is selected from hydrogen, sodium or potassium, m ═ 0, p ═ 1, a is selected from ethylene, linear propylene or linear butylene.

Alternatively, the heptamethine carboxyindocyanine dye has a structural formula shown in formula (I-1), formula (I-2) or formula (I-3):

alternatively, R in formula (I) is selected from R₁And R₂One of (1); wherein the content of the first and second substances,

when R is R₁When R' is selected from hydrogen, carboxyl or ester group, a is selected from 2, 4, 6 or 8, X is selected from bromine or iodine, m is 1, p is 0, A is selected from ethylene or linear propylene; or

R' is selected from carboxylate or sulfonate, a is selected from 3, 5, 7 or 9, Y is selected from sodium, m ═ 0, p ═ 1, a is selected from ethylene or linear propylene;

when R is R₂When R "is selected from hydrogen, carboxyl or ester group, b is selected from 0, 1, 3 or 5, X is selected from bromine or iodine, m ═ 1, p ═ 0, a is selected from ethylene or linear propylene; or

R "is selected from carboxylate or sulfonate, b is selected from 0, 1, 3 or 5, Y is selected from sodium, m ═ 0, p ═ 1, and a is selected from ethylene or linear propylene.

The application relates to a heptamethine carboxyl indole cyanine dye containing side chains of N-aliphatic acid, N-aliphatic ester, N-aliphatic amide, N-aliphatic chain hydrocarbon, N-aromatic acid, N-aromatic ester, N-aromatic amide or N-aromatic chain hydrocarbon and the like, and a synthesis and purification method thereof. The heptamethine carboxyl indocyanine dye has or independently has the performances of near infrared light absorption and fluorescence development. The method has the advantages of short synthetic route, environment-friendly solvent, simple process, avoidance of noble metal catalysis, high yield and simple purification method (no chromatographic column separation is needed and less solvent is consumed), can greatly improve the preparation efficiency of the dye, realizes low-cost batch production, and has great significance in the production and application research of the heptamethine carboxyl indocyanine.

As a specific embodiment, the heptamethine carboxyindocyanine dye herein is selected from compounds having the structural formula shown below:

(1) when A is a linear propylene group, R is selected from R₁R' is selected from hydrogen, when a is 2,3, 4, 6 and 12, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 1-5;

(2) when A is a linear propylene group, R is selected from R₁R' is selected from carboxylate radical, when a is 1, 2,3 and 5, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 6-9;

(3) when A is a linear propylene group, R is selected fromR₁R' is selected from an ethyl ester group, and when a is 1, 2,3 and 5, the heptamethine carboxyl indole cyanine dyes are compounds with structural formulas 10-13 respectively;

(4) when A is a linear propylene group, R is selected from R₁R' is selected from hydroxyl, and when a is 2,3, 4 and 6, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 14-17;

(5) when A is a linear propylene group, R is selected from R₁R' is selected from methoxy, and when a is 2, 4 and 6, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 18-20;

(6) when A is a linear propylene group, R is selected from R₁R' is selected from amide groups, and when a is 1, 2,3 and 5, the heptamethine carboxyl indole cyanine dyes are compounds with a structural formula of 21-24 respectively;

(7) when A is a linear propylene group, R is selected from R₂Wherein R "is selected from hydrogen, and when b ═ 0, the heptamethine carboxyindocyanine dye is a compound having structural formula 25;

(8) when A is a linear propylene group, R is selected from R₂R' is selected from carboxyl, when b is 0, 1 and 3, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 26-28;

(9) when A is a linear propylene group, R is selected from R₂R' is selected from sulfonic acid group, when b is 0, 1,4, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 29-31;

(10) when A is a linear propylene group, R is selected from R₂When R' is selected from methyl, and b is 0, 1, 3 and 5, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 32-35;

(11) when A is a linear propylene group, R is selected from R₂R' is selected from carbomethoxy, when b is 0, 1, 3 and 5, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 36-39;

(12) when A is a linear propylene group, R is selected from R₂When R' is selected from methoxy, and b is 0, 1, 3 and 4, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 40-43;

(13) when A is a linear propylene group, R is selected from R₂R' is selected from amide groups, and when b is 0, 1, 2 and 3, the heptamethine carboxyl indole cyanine dyes are compounds with structural formulas 44-47 respectively;

(14) when A is a linear propylene group, R is selected from R₁R' is selected from ethynyl, when a ═ 3, the heptamethine carboxyl indole cyanine dye is a compound having a structural formula 48;

(15) when A is a linear propylene group, R is selected from R₂Wherein R "is selected from amino, and when b ═ 0, the heptamethine carboxyindocyanine dye is a compound having structural formula 49;

(16) when A is a linear propylene group, R is selected from R₂Wherein R "is selected from hydroxy, and when b ═ 0, the heptamethine carboxyindocyanine dye is a compound having a structural formula 50;

(17) when A is ethylene, R is selected from R₁R' is selected from hydrogen, when a is 2,3, 4, 6 and 12, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 51-55;

(18) when A is ethylene, R is selected from R₁R' is selected from carboxylate radical, when a is 1, 2,3 and 5, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 56-59;

(19) when A is ethylene, R is selected from R₁R' is selected from an ethyl ester group, and when a is 1, 2,3 and 5, the heptamethine carboxyl indole cyanine dyes are compounds with a structural formula of 60-63;

(20) when A is ethylene, R is selected from R₁R' is selected from hydroxyl, and when a is 2,3, 4 and 6, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 64-67;

(21) when A is ethylene, R is selected from R₁R' is selected from methoxy, and when a is 2, 4 and 6, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 68-70;

(22) when A is ethylene, R is selected from R₁R' is selected from amide groups, and when a is 1, 2,3 and 5, the heptamethine carboxyl indole cyanine dyes are compounds with structural formulas of 71-74;

(23) when A is ethylene, R is selected from R₂Wherein R "is selected from hydrogen, and when b ═ 0, the heptamethine carboxyindocyanine dye is a compound having a structural formula 75;

(24) when A is ethylene, R is selected from R₂R' is selected from carboxyl, when b is 0, 1 and 3, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 76-78;

(25) when A is ethylene, R is selected from R₂R' is selected from sulfonic acid group, when b is 0, 1,4, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 79-81;

(26) when A is ethylene, R is selected from R₂When R' is selected from methyl and b is 0, 1, 3 and 5, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 82-85;

(27) when A is ethylene, R is selected from R₂R' is selected from carbomethoxy, when b is 0, 1, 3 and 5, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 86-89;

(28) when A is ethylene, R is selected from R₂When R' is selected from methoxy, and b is 0, 1, 3 and 4, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 90-93;

(29) when A is ethylene, R is selected from R₂R' is selected from amide groups, and when b is 0, 1, 2 and 3, the heptamethine carboxyl indole cyanine dyes are compounds with a structural formula of 94-97 respectively;

(30) when A is ethylene, R is selected from R₁R' is selected from ethynyl, when a ═ 3, the heptamethine carboxyl indole cyanine dye is a compound having a structural formula 98;

(31) when A is ethylene, R is selected from R₂Wherein R' is selected from amino, when b is 0, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula of 99;

(32) when A is ethylene, R is selected from R₂And when R' is selected from hydroxyl and b is 0, the heptamethine carboxyl indole cyanine dye is a compound with a structural formula 100.

According to another aspect of the present application, a method for preparing the heptamethine carboxyindocyanine dye is provided. The method has the advantages of short synthetic route, environment-friendly solvent, simple process, avoidance of noble metal catalysis, high yield and large single reaction amount, can greatly improve the preparation efficiency of the dye, and realizes low-cost mass production. In addition, the method has strong applicability and can be used for preparing heptamethine carboxyl indole cyanine dyes with various structural types.

The preparation method of the heptamethine carboxyl indole cyanine dye is characterized by comprising the following steps:

1) reacting raw materials containing 2,3, 3-trimethyl-carboxyl indole derivatives and nucleophilic substitution compounds at 80-130 ℃ for 4-24 hours under a vacuum condition to obtain organic ammonium salt;

wherein, the structural formula of the 2,3, 3-trimethyl-carboxyl indole derivative is shown as the formula (III-1):

the nucleophilic substitution compound is selected from at least one compound with a structural formula shown as a formula (III-2), a formula (III-3) or a formula (III-4):

in the formula (III-2)，R¹Selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, a is selected from an integer which is more than 0 and less than or equal to 14, and X is selected from fluorine, chlorine, bromine, iodine or perchlorate; in the formula (III-3), R²Is selected from

c is an integer from 1 to 13; in the formula (III-4), R³Selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amido, sulfonic acid group, ester group, alkynyl or amino, b is selected from an integer of 0 to 7, and X is selected from fluorine, chlorine, bromine, iodine or perchlorate;

the structural formula of the organic ammonium salt is shown as a formula (III-5), a formula (III-6) or a formula (III-7):

in the formula (III-5), R¹A and X are as defined in formula (III-2), and m is 1; in the formula (III-6), R^2'Selected from the group consisting of carboxylate and sulfonate, c being as defined in formula (III-3); in the formula (III-7), R³B and X are as defined in formula (III-4), and m is 1;

2) reacting the solution containing the organic ammonium salt and the cycloolefine derivative obtained in the step 1) for 8-48 hours at 50-80 ℃ under a closed condition to obtain the heptamethine carboxyl indole cyanine dye;

wherein the structural formula of the cycloalkene derivative is shown as a formula (III-8):

in the formula (III-8), A is selected from ethylene, linear propylene or linear butylene.

Alternatively, the structural formula of the cycloalkene derivative is shown as formula (III-8-1), formula (III-8-2) or formula (III-8-3):

optionally, in the step 1), the molar ratio of the 2,3, 3-trimethyl-carboxyindole derivative to the nucleophilic substitution compound is 1: 1-1: 12.

Alternatively, in step 1), the upper limit of the molar ratio of the 2,3, 3-trimethyl-carboxyindole derivative to the nucleophilic substitution compound is selected from 1:12, 1:11, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, and the lower limit is selected from 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1: 11.

Preferably, in the step 1), the molar ratio of the 2,3, 3-trimethyl-carboxyl indole derivative to the nucleophilic substitution compound is 1: 1-1: 2.

More preferably, in step 1), the molar ratio of the 2,3, 3-trimethyl-carboxyindole derivative to the nucleophilic substitution compound is 1: 1.5.

Optionally, in step 1), the upper limit of the temperature for reacting the raw materials is selected from 130 ℃, 125 ℃, 120 ℃, 115 ℃, 110 ℃, 105 ℃, 100 ℃, 95 ℃, 90 ℃, and the lower limit is selected from 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃; the upper limit of the time for reacting the raw materials is selected from 24 hours, 23 hours, 22 hours, 20 hours, 18 hours, 16 hours, 15 hours, 14 hours, 12 hours, 10 hours, and 5 hours, and the lower limit is selected from 4 hours, 5 hours, 8 hours, 10 hours, 12 hours, 14 hours, 15 hours, 16 hours, 18 hours, 20 hours, 22 hours, and 23 hours.

Preferably, in the step 1), the raw materials are reacted for 8-16 hours at 100-120 ℃.

More preferably, in the step 1), the raw materials are reacted for 10 to 14 hours at a temperature of 110 to 120 ℃.

Particularly preferably, in step 1), the starting materials are reacted at 120 ℃ for 12 hours.

Alternatively, in step 1), the starting materials are reacted under closed conditions.

Optionally, in the step 1), the raw materials are reacted under the pressure of 2-200 Pa.

Alternatively, in step 1), the upper limit of the pressure for reacting the raw material is selected from 200Pa, 175Pa, 150Pa, 125Pa, 100Pa, 75Pa, 50Pa, 40Pa, 30Pa, 20Pa, 10Pa, 9Pa, 8Pa, 7Pa, 6Pa, 5Pa, 4Pa, 3Pa, and the lower limit is selected from 2Pa, 3Pa, 4Pa, 5Pa, 6Pa, 7Pa, 8Pa, 9Pa, 10Pa, 20Pa, 30Pa, 40Pa, 50Pa, 75Pa, 100Pa, 125Pa, 150Pa, 175 Pa.

Preferably, in the step 1), the raw materials are reacted under the pressure of 5-50 Pa.

More preferably, in step 1), the starting materials are reacted at a pressure of 10 Pa.

In the method according to the present application, there is no particular limitation as to whether a reaction medium is used in addition to the reactants in step 1), as long as the reactants are capable of completing the reaction of step 1). That is, under the reaction conditions of step 1) as described above, when a liquid phase is present in the reaction system (for example, in the case where at least a part of the reactants is in a liquid state), the reaction medium need not be used, or may be used.

Optionally, the reaction medium is an alcohol-based reaction medium for purposes such as environmental protection and safety.

Preferably, the reaction medium is selected from at least one of methanol, ethanol, propanol, ethylene glycol, glycerol, butanol and butanediol.

Optionally, in the step 2), the molar ratio of the cycloalkene derivative to the organic ammonium salt is 1: 2-1: 6.

Optionally, in step 2), the upper limit of the molar ratio of the cycloalkene derivative to the organic ammonium salt is selected from 1:6, 1:5.5, 1:5, 1:4.5, 1:4, 1:3.8, 1:3.5, 1:3.4, 1:3.2, 1:3, 1:2.8, 1:2.5, 1:2.4, 1:2.2, 1:2.1, and the lower limit is selected from 1:2, 1:2.1, 1:2.2, 1:2.4, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.4, 1:3.5, 1:3.8, 1:4, 1:4.5, 1:5, 1: 5.5.

Preferably, in the step 2), the molar ratio of the cycloalkene derivative to the organic ammonium salt is 1: 2-1: 3.

More preferably, in step 2), the molar ratio of the cycloalkene derivative to the organic ammonium salt is 1: 2.5.

Optionally, in step 2), the solution is reacted at a temperature with an upper limit selected from 80 ℃, 75 ℃, 70 ℃, 65 ℃, 60 ℃, 55 ℃, and a lower limit selected from 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃; the upper limit of the time for reacting the solution is selected from 48 hours, 38 hours, 35 hours, 32 hours, 30 hours, 28 hours, 24 hours, 20 hours, 18 hours, 15 hours, 10 hours, and the lower limit is selected from 8 hours, 10 hours, 15 hours, 18 hours, 20 hours, 24 hours, 28 hours, 30 hours, 32 hours, 35 hours, 38 hours.

Preferably, in the step 2), the solution is reacted for 10 to 30 hours at a temperature of 60 to 80 ℃.

More preferably, in the step 2), the solution is reacted for 10 to 30 hours at a temperature of 70 to 80 ℃.

More preferably, in the step 2), the solution is reacted for 15-28 hours at 70-80 ℃.

Particularly preferably, in step 2), the solution is reacted at 75 ℃ for 24 hours.

Optionally, in the step 2), a precipitator is added after the reaction, the reaction is kept at the temperature of 1-10 ℃ for 12-48 hours, and then the reaction is filtered, so that the heptamethine carboxyl indole cyanine dye is obtained.

Optionally, in step 2), the upper limit of the temperature maintained after adding the precipitant is selected from 10 ℃, 9 ℃, 8 ℃, 7 ℃, 6 ℃, 5 ℃,4 ℃,3 ℃, 2 ℃, and the lower limit is selected from 1 ℃, 2 ℃,3 ℃,4 ℃, 5 ℃, 6 ℃, 7 ℃, 8 ℃, 9 ℃; the upper limit of the time for holding is selected from 48 hours, 44 hours, 40 hours, 36 hours, 32 hours, 28 hours, 24 hours, 20 hours, 16 hours, and the lower limit is selected from 12 hours, 16 hours, 20 hours, 24 hours, 28 hours, 32 hours, 36 hours, 40 hours, 44 hours.

Preferably, in the step 2), a precipitator is added after the reaction, and the mixture is maintained at 4 ℃ for 24 hours and then is filtered by suction to obtain the heptamethine carboxyl indocyanine dye.

Optionally, the precipitant is selected from at least one of petroleum ether, diethyl ether, dimethyl ether, propyl ether, and methyl ethyl ether.

Preferably, the precipitating agent comprises petroleum ether.

Optionally, in step 2), the solvent in the solution is selected from at least one of water, methanol, ethanol, propanol, ethylene glycol, glycerol, butanol and butanediol.

Preferably, in step 2), the solvent in the solution is selected from at least one of methanol, ethanol and propanol.

Thus, as regards the solvent, in step 1) of the process according to the present application, depending on the state of the reactants, it is possible to use no solvent, or it is possible to use a solvent and to select from alcohols; in step 2), a solvent selected from water and alcohols may be used. The solvent usable in the present application is more environmentally friendly and safe and less harmful to health than solvents such as o-dichlorobenzene, acetic anhydride used in conventional methods.

In one embodiment, a method for preparing a 2,3, 3-trimethyl-carboxyindole derivative comprises the steps of:

1) dissolving p-carboxyl phenylhydrazine, 3-methyl-2-butanone and anhydrous sodium acetate in acetic acid for reaction;

2) removing the reaction solvent, and adding a mixed solution of water and methanol to dissolve the residual substances;

3) the resulting material was filtered and crystallized to give 2,3, 3-trimethyl-carboxyindole as crystals.

Optionally, in the step 1), the molar ratio of the p-carboxyphenylhydrazine, the 3-methyl-2-butanone and the anhydrous sodium acetate is 1: 1-1.2: 1.4-1.6, and is preferably 1:1.1: 1.5.

Optionally, in the step 1), the reaction is performed under reflux and stirring for 6 to 10 hours, preferably 8 hours.

Optionally, in the step 2), the volume ratio of the water to the methanol is 8: 1-10: 1, and is preferably 9: 1.

Optionally, in the step 3), the crystallization is performed in an open manner at room temperature for 36-50 hours, preferably 48 hours.

In a particular embodiment, the synthesis of the 2,3, 3-trimethyl-carboxyindole derivative is carried out according to the following steps:

p-carboxyphenylhydrazine, 3-methyl-2-butanone and anhydrous sodium acetate in a molar ratio of 1:1.1:1.5 are dissolved in acetic acid and reacted for 8 hours under reflux and stirring. The reaction solvent was removed by rotary evaporation, and thereafter a mixed solution of water and methanol was added in a volume ratio of 9:1 to dissolve the remaining substances. The resultant was filtered and then left to crystallize in the open at room temperature for 48 hours to give 2,3, 3-trimethyl-4-carboxyindole as a crystal.

Alternatively, the heptamethine carboxyindocyanine dye prepared by the methods described herein has a purity greater than 90%.

Optionally, the purity of the heptamethine carboxyindocyanine dye prepared by the method is 85-99.5%.

Optionally, the purity of the heptamethine carboxyindocyanine dye prepared by the method is 90-99.5%.

Alternatively, the yield of the heptamethine carboxyindocyanine dye prepared by the method described herein is not less than 83.5%.

Optionally, the yield of the heptamethine carboxyindocyanine dye prepared by the method described herein is 83.5-93.7%.

As a specific embodiment, the preparation method of the heptamethine carboxyl indole cyanine dye is carried out according to the following scheme:

x is selected from one of halogen, preferably bromine; r is a group consisting of a linear alkylene group having 1 to 14 carbon atoms and a terminal group selected from hydrogen, methyl, methoxy, hydroxyl, carboxyl, amide, sulfonic acid, ester, alkynyl or amino;

wherein the molar ratio of the 2,3, 3-trimethyl-carboxyl indole to the bromine substituent (X-R) as the nucleophilic substitution compound is 1: 1-1: 12, preferably 1: 1.5; the heating temperature is 80-130 ℃, and preferably 120 ℃; the molar ratio of 2-chloro-1-formyl-3-hydroxymethylcyclohexene serving as a cycloalkene derivative to an N-substituent serving as an organic ammonium salt is 1: 2-1: 4, preferably 1: 2.5; the heating temperature is 50-80 ℃, and preferably 75 ℃.

As a specific embodiment, the preparation method of the heptamethine carboxyl indocyanine dye comprises the following steps:

1) fully mixing 2,3, 3-trimethyl-carboxyl indole and a bromine substituent (X-R) as a nucleophilic substituent compound, and heating for reaction under a vacuum condition, wherein the molar ratio of the 2,3, 3-trimethyl-carboxyl indole to the bromine substituent is 1: 1-1: 12, the heating temperature is 80-130 ℃, and the reaction time is 4-24 hours; preferably, the molar ratio of 2,3, 3-trimethyl-carboxyindole to bromine substituent is 1:1.5, the heating temperature is 120 ℃ and the reaction time is 12 hours.

2) Adding 2-chloro-1-formyl-3-hydroxymethylcyclohexene serving as a cycloalkene derivative into the solution reacted in the step 1), heating to react under a closed condition, placing the reacted solution in a refrigerator at 4 ℃ for overnight after the reaction, and precipitating by using a precipitator, wherein the molar ratio of the 2-chloro-1-formyl-3-hydroxymethylcyclohexene to an N-substituent serving as an organic ammonium salt is 1: 2-1: 4, the heating temperature is 50-80 ℃, and the reaction time is 8-48 hours; preferably, the molar ratio of 2-chloro-1-formyl-3-hydroxymethylcyclohexene to the N-substituent is 1:2.5, the heating temperature is 75 ℃, and the reaction time is 24 hours.

According to yet another aspect of the present application, there is provided the use of the heptamethine carboxyindocyanine dye.

Optionally, the heptamethine carboxyl indole cyanine dye is used for preparing a probe auxiliary agent, and the probe auxiliary agent comprises at least one of the heptamethine carboxyl indole cyanine dye and the heptamethine carboxyl indole cyanine dye prepared by the method.

Optionally, the heptamethine carboxyl indole cyanine dye is applied to preparation of a near-infrared fluorescent probe.

Optionally, the near-infrared fluorescent probe comprises a small molecule probe and a nano probe.

Optionally, the heptamethine carboxyl indole cyanine dye is applied to the fields of trademark anti-counterfeiting, biomedicine, environmental monitoring, national defense detection and correlation thereof.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

In the present application, the term "alkyl" means a group formed by losing any one hydrogen atom on the molecule of an alkane compound; the alkane compound comprises cycloalkane, straight-chain alkane and branched alkane.

In the present application, the term "ethylene" means a compound of the formula-CH₂-CH₂The radical of (A) and (B), the term "linear propylene" means a radical of the formula-CH₂-CH₂-CH₂The radical of (A) and (B), the term "linear butylene" means a radical of the formula-CH₂-CH₂-CH₂-CH₂-a group of (a).

All conditions in this application that relate to a numerical range can be independently selected from any point within the numerical range.

The present application has the following benefits, including but not limited to:

1) the heptamethine carboxyl indocyanine dye provided by the application has the performances of near infrared light absorption and fluorescence development.

2) The preparation method of the heptamethine carboxyl indole cyanine dye has the advantages of short synthetic route, environment-friendly solvent, simple process, avoidance of noble metal catalysis, high yield and large single reaction amount, can greatly improve the preparation efficiency of the dye, and realizes low-cost batch production.

3) The heptamethine carboxyl indole cyanine dye obtained by the preparation method provided by the application has high purity which can be higher than 90%.

4) The preparation method of the heptamethine carboxyl indole cyanine dye provided by the application has strong applicability, and can be used for realizing the synthesis of products with various structure types.

Drawings

Fig. 1 is an infrared absorption spectrum of compound C1 prepared according to example 5 of the present application.

Fig. 2 is a graph showing the effect of compound C1 prepared according to example 5 of the present application on in vivo imaging of mice after intravenous injection for 48 hours.

Detailed Description

As mentioned above, the present application relates to a method for preparing heptamethine carboxyl indocyanine dye, comprising the following steps: reacting the 2,3, 3-trimethyl-carboxyl indole derivative with a nucleophilic substitution compound to obtain an organic ammonium salt; mixing organic ammonium salt and a cycloolefine derivative in an environment-friendly organic solvent for reaction, adding an organic precipitator into a product after the reaction, cooling and standing overnight to obtain the heptamethine carboxyl indole cyanine dye. The method has the advantages of short synthetic route, simple process, no catalyst, high yield, simple purification method, high atom utilization rate and less consumption of organic solvent, can greatly improve the preparation efficiency of the dye, realizes low-cost batch production, and has great significance in the production and application research of the heptamethine carboxyl indole cyanine dye.

In addition, the preparation method of the heptamethine carboxyl indocyanine dye has wider applicability. The method can realize the synthesis of products with more structural types under the conditions of adopting more environment-friendly solvents and milder reaction conditions.

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials and reagents in the examples of the present application were all purchased commercially.

The analysis method in the examples of the present application is as follows:

infrared absorption spectrum analysis was performed using a ThermoNciolet model 6700 infrared spectrometer.

UV absorption spectroscopy was performed using a Perkinelmer Lanbda type UV spectrophotometer.

In vitro fluorescence detection analysis was performed using a Perkinelmer IVIS Lumina LT model small animal imager.