Summary of the invention
At the deficiencies in the prior art part, the invention provides the synthetic method of a kind of environmental friendliness, technology is simple, cost is low, yield is high S-(-)-indoline-2-carboxylic acid.
The present invention is for reaching above purpose, and be to realize by such technical scheme: the synthetic method that a kind of S-(-)-indoline-2-carboxylic acid is provided: with the L-phenylalanine is raw material, may further comprise the steps successively:
1), chlorination: with L-phenylalanine, solvent and ethanol under agitation condition, feed chlorine and carry out chlorination reaction, the weight ratio of L-phenylalanine and solvent is 1: 7~1: 12, consumption of ethanol is 10%~31% of a L-phenylalanine amount of substance, temperature of reaction is 10~30 ℃, and the reaction times is 0.5~2 hour; With the hydrochloride crystal of described chlorination reaction gained be hydrolyzed successively, vacuum removal solvent, washing, drying step, L-2,4-dichlorobenzene L-Ala;
2), cyclization: with above-mentioned L-2,4-dichlorobenzene L-Ala carries out ring-closure reaction in solvent, under the effect of copper salt catalyst, L-2, and the weight ratio of 4-dichlorobenzene L-Ala and solvent is 1: 1~1: 3, the weight of copper salt catalyst is L-2,5%~15% of 4-dichlorobenzene L-Ala; Temperature of reaction is 100~140 ℃, 2~6 hours reaction times; After reaction finishes, extract successively again, wash, dry, remove solvent step, S-indoline-6-chloro-2-carboxylic acid;
3), reduction: above-mentioned S-indoline-6-chloro-2-carboxylic acid and sodium, the trimethyl carbinol are carried out back flow reaction in solvent, the weight ratio of described S-indoline-6-chloro-2-carboxylic acid and solvent is 1: 4~1: 8.2, and the consumption of the sodium and the trimethyl carbinol is 1~3 times of amount of substance of S-indoline-6-chloro-2-carboxylic acid; Solvent step is filtered, removed to reaction after finishing again successively.
A kind of improvement as S-of the present invention (-)-indoline-2-carboxylic acid synthetic method: earlier S-indoline-6-chloro-2-carboxylic acid is mixed with partial solvent in the reduction reaction of step 3), be made into concentration and be S-indoline-6-chloro-2-carboxylic acid solution of 49%, described S-indoline-6-chloro-2-carboxylic acid solution is added in the mixture that sodium, the trimethyl carbinol, residual solvent forms in the mode that drips carry out back flow reaction again.
Further improvement as S-of the present invention (-)-indoline-2-carboxylic acid synthetic method: the reflux time of step 3) is 2~6 hours.
Further improvement as S-of the present invention (-)-indoline-2-carboxylic acid synthetic method: be hydrolyzed with frozen water in the hydrolysing step of step 1).
Further improvement as S-of the present invention (-)-indoline-2-carboxylic acid synthetic method: solvent for use is a halides in the chlorination reaction of step 1), for example chloroform or tetracol phenixin.
As S-of the present invention (-)-draw the further improvement of diindyl quinoline-2-carboxylic acid synthetic method: used copper salt catalyst is cupric chloride or cuprous chloride in ring-closure reaction step 2).
Further improvement as S-of the present invention (-)-indoline-2-carboxylic acid synthetic method: solvent for use is a diethanolamine in ring-closure reaction step 2).
Further improvement as S-of the present invention (-)-indoline-2-carboxylic acid synthetic method: solvent for use is a tetrahydrofuran (THF) in the reduction reaction of step 3).
Reaction formula is as follows:
The synthetic method of S-of the present invention (-)-indoline-2-carboxylic acid, with chiral organic compound---the L-phenylalanine is a raw material, through the synthetic S-(-) of superchlorination, cyclization and reduction three-step reaction-indoline-2-carboxylic acid.Route of the present invention, has omitted splitting step, has simplified technological operation so building-up process does not need to split because to have adopted the compound that has an identical configuration with target product be raw material.Raw material L-phenylalanine at present can scale operation, therefore can reduce production costs.The synthetic method of S-of the present invention (-)-indoline-2-carboxylic acid is compared with the technology that in the past synthetic racemic modification splits again, have that operational path is short, yield is high (in the L-phenylalanine, high energy reaches 36.5%), the advantage that the products obtained therefrom optical activity is high.
Embodiment
Raw material L-phenylalanine specific rotation is
(c=2.0, H
2O)
The synthetic method of embodiment 1:S-(-)-indoline-2-carboxylic acid is main starting raw material with the L-phenylalanine, makes through following step successively:
(1) chlorination, i.e. L-2, the preparation of 4-dichlorobenzene L-Ala:
Add 208g (1.26mol) L-phenylalanine and 1600g in the there-necked flask of 2000ml with the dry tetracol phenixin of crossing of Calcium Chloride Powder Anhydrous, add 7.2ml (0.126mol) dehydrated alcohol again, under agitation condition, feed chlorine about 10 ℃, begin to separate out crystal of hydrochloride this moment, continue to stop to feed behind the logical chlorine 1h.The gas except that HCl is caught up with in heating, adds 400ml frozen water hydrolysis hydrochloride again; Separate out L-2 behind the vacuum removal solvent, 4-dichlorobenzene L-Ala solid, the petroleum ether after drying gets this step product 130g, 243~245 ℃ of fusing points (dec.), yield 44%.
(2) cyclization, the i.e. preparation of S-indoline-6-chloro-2-carboxylic acid:
Add diethanolamine 100g in the 1000ml there-necked flask, cupric chloride 5g adds 100g (0.42mol) L-2 after stirring is warming up to 100 ℃ in batches, and 4-dichlorobenzene L-Ala after the dissolving, keeps 100 ℃ to continue reaction 4h fully.Finish the reaction back with the 200ml ethyl acetate extraction, extraction phase with the 100ml water washing after with anhydrous sodium sulfate drying, decompression removes solvent, get pale solid-S-indoline-6-chloro-2-carboxylic acid, the petroleum ether after drying, get this step product 25g, 203~204 ℃ of fusing points (dec.), yield 30%.
(3) reduction, i.e. the preparation of S-(-)-indoline-2-carboxylic acid:
Add 75g tetrahydrofuran (THF) and 8.5g (0.37mol) sodium sand in the 500ml there-necked flask, add the new trimethyl carbinol 27.5g (0.37mol) that steams under the violent stirring and make mixture.At this moment, Dropwise 5 0g is dissolved with the tetrahydrofuran solution of 24.5g (0.125mol) S-indoline-6-chloro-2-carboxylic acid (promptly by the tetrahydrofuran (THF) mixing gained of 24.5g S-indoline-6-chloro-2-carboxylic acid with 25.5g in said mixture in 30 minutes, concentration is S-indoline-6-chloro-2-carboxylic acid solution of 49%), back flow reaction 2 hours.Reaction finishes after-filtration and removes unreacted sodium, remove behind the solvent product S-(-)-indoline-2-carboxylic acid, drying, the 14g product, 184~186 ℃ of fusing points,
(c=1.0, DMSO), yield 68.3%.
The synthetic method of embodiment 2:S-(-)-indoline-2-carboxylic acid is main starting raw material with the L-phenylalanine, makes through following step successively:
(1) chlorination, i.e. L-2, the preparation of 4-dichlorobenzene L-Ala:
Add 208g (1.26mol) L-phenylalanine and 2000g in the there-necked flask of 2000ml with the dry tetracol phenixin of crossing of Calcium Chloride Powder Anhydrous, add 14.4ml (0.256mol) dehydrated alcohol again, under agitation condition, feed chlorine about 20 ℃, begin to separate out crystal of hydrochloride this moment, continue to stop to feed behind the logical chlorine 1.5h.The gas except that HCl is caught up with in heating, adds 400ml water hydrolysis hydrochloride again.Separate out L-2 behind the vacuum removal solvent, 4-dichlorobenzene L-Ala solid, the petroleum ether after drying gets this step product 188g, 243~245 ℃ of fusing points (dec.), yield 63.2%.
(2) cyclization, the i.e. preparation of S-indoline-6-chloro-2-carboxylic acid:
Add diethanolamine 200g in the 1000ml there-necked flask, cupric chloride 10g adds 100g (0.42mol) L-2 after stirring is warming up to 100 ℃ in batches, and 4-dichlorobenzene L-Ala after the dissolving, keeps 120 ℃ to continue reaction 2h fully.Finish the reaction back with the 200ml ethyl acetate extraction, extraction phase with the 100ml water washing after with anhydrous sodium sulfate drying, decompression removes solvent, get pale solid-S-indoline-6-chloro-2-carboxylic acid, the petroleum ether after drying, get this step product 28g, 203~204 ℃ of fusing points (dec.), yield 33.4%.
(3) reduction, i.e. the preparation of S-(-)-indoline-2-carboxylic acid:
Add 125g tetrahydrofuran (THF) and 2.88g (0.125mol) sodium sand in the 500ml there-necked flask, add the new trimethyl carbinol 9.25g (0.125mol) that steams under the violent stirring.At this moment, Dropwise 5 0g is dissolved with the tetrahydrofuran solution of 24.5g (0.125mol) S-indoline-6-chloro-2-carboxylic acid, back flow reaction 4 hours in 30 minutes.Reaction finishes after-filtration and removes unreacted sodium, remove behind the solvent product S-(-)-indoline-2-carboxylic acid, drying, the 9g product, 184~186 ℃ of fusing points,
(c=1.0, DMSO), yield 43.9%.
The synthetic method of embodiment 3:S-(-)-indoline-2-carboxylic acid is main starting raw material with the L-phenylalanine, makes through following step successively:
(1) chlorination, i.e. L-2, the preparation of 4-dichlorobenzene L-Ala:
Add 104g (0.63mol) L-phenylalanine and 1200g in the there-necked flask of 1000ml with the dry tetracol phenixin of crossing of Calcium Chloride Powder Anhydrous, add 10.8ml (0.192mol) dehydrated alcohol again, under agitation condition, feed chlorine about 30 ℃, begin to separate out crystal of hydrochloride this moment, continue to stop to feed behind the logical chlorine 2h.The gas except that HCl is caught up with in heating, adds 200ml water hydrolysis hydrochloride again.Separate out L-2 behind the vacuum removal solvent, 4-dichlorobenzene L-Ala solid, the petroleum ether after drying gets this step product 108g, 243~245 ℃ of fusing points (dec.), yield 72.6%.
(2) cyclization, the i.e. preparation of S-indoline-6-chloro-2-carboxylic acid:
Add diethanolamine 300g in the 1000ml there-necked flask, cupric chloride 15g adds 100g (0.42mol) L-2 after stirring is warming up to 100 ℃ in batches, and 4-dichlorobenzene L-Ala after the dissolving, keeps 140 ℃ of back flow reaction 6h fully.Finish the reaction back with the 200ml ethyl acetate extraction, extraction phase with the 100ml water washing after with anhydrous sodium sulfate drying, decompression removes solvent, get pale solid-S-indoline-6-chloro-2-carboxylic acid, the petroleum ether after drying, get this step product 54g, 203~204 ℃ of fusing points (dec.), yield 64.4%.
(3) reduction, i.e. the preparation of S-(-)-indoline-2-carboxylic acid
Add 350g tetrahydrofuran (THF) and 11.5g (0.5mol) sodium sand in the 1000ml there-necked flask, add the new trimethyl carbinol 37g (0.5mol) that steams under the violent stirring.At this moment, in 30 minutes, drip the tetrahydrofuran solution that 100g is dissolved with 49g (0.25mol) S-indoline-6-chloro-2-carboxylic acid, back flow reaction 6 hours.Reaction finishes after-filtration and removes unreacted sodium, remove behind the solvent product S-(-)-indoline-2-carboxylic acid, drying, the 32g product, 180~182 ℃ of fusing points,
(c=1.0, DMSO), yield 78.0%.
Embodiment 4: the synthetic method of a kind of S-(-)-indoline-2-carboxylic acid is main starting raw material with the L-phenylalanine, makes through following step successively:
(1) chlorination, i.e. L-2, the preparation of 4-dichlorobenzene L-Ala
Add 208g (1.26mol) L-phenylalanine and 1600g in the there-necked flask of 2000ml with the dry chloroform of crossing of Calcium Chloride Powder Anhydrous, add 7.2ml (0.126mol) dehydrated alcohol again, under agitation condition, feed chlorine about 20 ℃, begin to separate out crystal of hydrochloride this moment, continue to stop to feed behind the logical chlorine 0.5h.The gas except that HCl is caught up with in heating, adds 200ml water hydrolysis hydrochloride again.Separate out L-2 behind the vacuum removal solvent, 4-dichlorobenzene L-Ala solid, the petroleum ether after drying gets this step product 120g, 243~245 ℃ of fusing points (dec.), yield 40.4%.
(2) cyclization, the i.e. preparation of S-indoline-6-chloro-2-carboxylic acid
Add diethanolamine 100g in the 1000ml there-necked flask, cuprous chloride 10g adds 100g (0.42mol) L-2 after stirring is warming up to 100 ℃ in batches, and 4-dichlorobenzene L-Ala after the dissolving, keeps 100 ℃ to continue reaction 4h fully.Finish the reaction back with the 200ml ethyl acetate extraction, extraction phase with the 100ml water washing after with anhydrous sodium sulfate drying, decompression removes solvent, get pale solid-S-indoline-6-chloro-2-carboxylic acid, the petroleum ether after drying, get this step product 37g, 203~204 ℃ of fusing points (dec.), yield 44.2%.
(3) reduction, i.e. the preparation of S-(-)-indoline-2-carboxylic acid
Add 75g tetrahydrofuran (THF) and 8.5g (0.37mol) sodium sand in the 500ml there-necked flask, add the new trimethyl carbinol 27.5g that steams under the violent stirring.At this moment, Dropwise 5 0g is dissolved with the tetrahydrofuran solution of 24.5g (0.125mol) S-indoline-6-chloro-2-carboxylic acid, back flow reaction 2 hours in 30 minutes.Reaction finishes after-filtration and removes unreacted sodium, remove behind the solvent product S-(-)-indoline-2-carboxylic acid, drying, the 12g product, 184~186 ℃ of fusing points,
(c=1.0, DMSO), yield 58.5%.
At last, it is also to be noted that what more than enumerate only is several specific embodiments of the present invention.Obviously, the invention is not restricted to above embodiment, many distortion can also be arranged.All distortion that those of ordinary skill in the art can directly derive or associate from content disclosed by the invention all should be thought protection scope of the present invention.