Summary of the invention
Purpose of the present invention is exactly the defective at easy oxidative degradation of tiopronin and poor heat stability, and a kind of tiopronin amidate is provided, and it can overcome the above-mentioned defective of tiopronin, and has the identical drug effect of tiopronin.
Another object of the present invention has provided a kind of synthetic method for preparing tiopronin amidate.
The present invention is through research, after finding tiopronin and amino acid whose reaction generated tiopronin amidate, can improve the stability of tiopronin, both prevented that tiopronin from meeting the easy oxidative degradation of the water capacity, prevent again its meet the volatile and decomposition of thermal capacitance problem.Its reason is that amino acid is the oxidation inhibitor that uses in the medicine, tiopronin is prepared into amino acid salts stoped combining of tiopronin and oxygen, can prevent its oxidation.Improved the fusing point of medicinal substance simultaneously, its thermostability is obviously improved.And amino acid itself also is effective ingredient, and the drug action of tiopronin amidate is also higher than the drug action of single tiopronin.
Structural formula of the present invention is as follows:
Wherein R is the straight or branched alkyl of 1 to 20 carbon atom.
Tiopronin amidate described in the present invention is arginic acid salt, lysine salt, leucine salt, Isoleucine salt, glycinate, cystine salt, cysteine salt, tyrosine salt, L-Ala salt, phenylalanine salt, Histidine salt, Serine salt, Threonine salt, methionine salt, tryptophane salt, glutaminate, aspartate or Xie Ansuan salt.The arginic acid salt that the preferred structure formula is following,
Or the following lysine salt of structural formula
Tiopronin amidate of the present invention prepares by the following method:
Starting raw material is a tiopronin
With amino acid H
2N---R---COOH
Reaction formula:
Tiopronin of the present invention and the amino acid whose mole ratio that feeds intake are 1: 0.8~1: 1.2, preferred 1: 1.05.
The solvent that uses in the reaction process among the present invention is an ethanol as methyl alcohol, ethanol, propyl alcohol, acetone, acetonitrile or ethyl acetate, preferred solvent.
Embodiment
Below in conjunction with embodiment the present invention is further described:
Embodiment 1: the preparation of tiopronin arginic acid salt
Feed ratio:
Operation:
Tiopronin, L-arginine, ethanol are dropped in three mouthfuls of reaction flasks of 1000ml, stir, be heated to 50 ℃ of backflows, back flow reaction is after 3 hours, filtered while hot, and filtrate is put 5-10 ℃ of crystallisation by cooling in the refrigerator.After 5 hours, filter, the white crystals body, xln was put in the baking oven 80 ℃ of dryings 6 hours, white crystalline solid 196g, yield 94.8%, mp197-200 ℃.
The infrared absorption spectrum data of sample:
Absorption peak (cm
-1): 2957.92,1647.58,1604.88,1525.77,1457.23,1407.90,1386.21,1357.38,1335.77,1313.99,1246.37,1159.37,1012.96,670.43,555.97.
Embodiment 2: the preparation of tiopronin lysine salt
Feed ratio:
Working method is with embodiment 1: the 177g white crystalline solid, yield 93.4%, mp172-175 ℃.
The infrared absorption spectrum data of sample:
Absorption peak (cm
-1): 3328.57,2939.20,1646.85,1593.90,1521.17,1405.00,1357.70,1316.94,1023.31,904.87,701.58,550.03,420.12.
Embodiment 3:
Tiopronin, the phenylalanine salt ratio in 1: 0.8 is dropped in three mouthfuls of reaction flasks of 1000ml, add the 650ml ethyl acetate then and stir, be heated to 100 ℃ of backflows, back flow reaction is after 3 hours, filtered while hot, and filtrate is put 5-10 ℃ of crystallisation by cooling in the refrigerator.After 5 hours, filter, the white crystals body, xln was put in the baking oven 80 ℃ of dryings 6 hours, white crystalline solid 196g, yield 94.2%, mp195-200 ℃.
Embodiment 4:
Tiopronin, the Xie Ansuan salt ratio in 1: 1 is dropped in three mouthfuls of reaction flasks of 1000ml, add the 650ml acetonitrile then and stir, be heated to 80 ℃ of backflows, back flow reaction is after 3 hours, filtered while hot, and filtrate is put 5-10 ℃ of crystallisation by cooling in the refrigerator.After 5 hours, filter, the white crystals body, xln was put in the baking oven 80 ℃ of dryings 6 hours, white crystalline solid 196g, yield 93.2%, mp185-190 ℃.
Embodiment 5:
Tiopronin, the cystine salt ratio in 1: 1 is dropped in three mouthfuls of reaction flasks of 1000ml, add 650ml acetone then and stir, be heated to 90 ℃ of backflows, back flow reaction is after 3 hours, filtered while hot, and filtrate is put 5-10 ℃ of crystallisation by cooling in the refrigerator.After 5 hours, filter, the white crystals body, xln was put in the baking oven 80 ℃ of dryings 6 hours, white crystalline solid 206g, yield 95.0%, mp185-190 ℃.
Embodiment 6:
Compare A: tiopronin, B: tiopronin arginic acid salt, C: the stability of tiopronin lysine salt in water.
A, B, C are dissolved in respectively in the distilled water, are mixed with the aqueous solution of content 5%, pour in the 2ml ampoule, sealing by fusing is put in the constant temperature oven, 40 ℃, investigates 10 days under 60 ℃ of conditions.In 0,5, sampling respectively in 10 days, check related substance and content as follows:
Related substance is measured according to high performance liquid chromatography (HPLC method).
Chromatographic condition and system suitability test: with octadecylsilane chemically bonded silica is weighting agent, is moving phase with the 0.07mol/L potassium dihydrogen phosphate, and flow velocity is about per minute 1.0ml, and the detection wavelength is 210nm.Number of theoretical plate calculates by tiopronin should be not less than 2000.
Assay method: it is an amount of that precision takes by weighing this product, add moving phase make contain 0.5mg among every 1ml solution as need testing solution; It is an amount of to measure need testing solution, add moving phase make contain 5 μ g among every 1ml solution as prerun solution.Get prerun solution 20 μ l and inject liquid chromatograph, regulate detection sensitivity, the peak height that makes the principal constituent chromatographic peak is the 5%-10% of full range; Get need testing solution 20 μ l again, inject liquid chromatograph, the record color atlas is to 3.5 times of principal constituent peak retention time.
Assay is according to high effective liquid chromatography for measuring.
Chromatographic condition and system suitability test are with under the determination of related substances item.
Assay method: precision takes by weighing this product 1ml and puts in the 100ml measuring bottle, is diluted to scale with moving phase, shakes up, as need testing solution.Other gets the tiopronin reference substance, and accurate the title decides, and makes the solution that contains 0.5mg among every 1ml, solution in contrast with moving phase.Get each 20 μ l of need testing solution and reference substance solution and inject liquid chromatograph, the record color atlas is pressed external standard method with calculated by peak area, promptly.
Measurement result sees Table 1:
As can be seen, at 40 ℃, under 60 ℃ of influence factor conditions, tiopronin arginic acid salt, tiopronin lysine salt are all stable than tiopronin in water.Wherein the tiopronin arginic acid salt is better than tiopronin lysine salt-stable.
Embodiment 7:
Compare A: tiopronin, B: tiopronin arginic acid salt, C: the stability of tiopronin lysine salt under the strong illumination condition.
Get A, B respectively, C is an amount of, puts into moisture eliminator, places under the injection clarity determinator, with 3000Lx illuminance irradiation 10 days, in 0,5, related substance and content were measured in sampling respectively in 10 days.
Detection method is with embodiment 3.
Measurement result sees Table 2:
As can be seen, the ordering of the stability of A, B, C is under 10 days strong illuminations: tiopronin arginic acid salt>tiopronin lysine salt>tiopronin.
From example 6,7 as can be seen, the amino acid salts of tiopronin is more stable than tiopronin.This provides a kind of good approach for the stability of improving tiopronin.