Preparation method for S-indoxacarb

Abstract

A catalyst and a method for preparing S-indoxacarb using the catalyst. The catalyst is prepared using 3-tert-butyl-5-(chloromethyl)salicylaldehyde and cyclohexanediamine as raw materials, where an original quinine catalyst such as cinchonine is replaced with the catalyst for application in the asymmetric synthesis of tert-butyl hydroperoxide and 5-chloro-2-methoxycarbonyl-1-indanone ester, greatly improving selection in the asymmetric synthesis process, with the S-enantiomer content increasing from 75% to over 98%, achieving the recycling of a high-efficiency chiral catalyst, and greatly reducing production costs. The synthesis process of the catalyst is simple and is favorable for industrialization, and lays good foundations for the production of high-quality indoxacarb.

Claims

1. A preparation method for S-indoxacarb, wherein a synthetic reaction is catalyzed by a chiral catalyst containing zirconium, a method of producing the chiral catalyst containing zirconium, comprising the steps of: step 1 (a) add 3-tert-butyl-5-(chloromethyl)salicylaldehyde and solvent to a reaction flask at 20-30° C.; (b) add chiral cyclohexanediamine to the flask dropwise at a drop rate of 0.1 mL/min; after addition of chiral cyclohexanediamine is complete, step 2 (a) raise the temperature to 40-80° C.; (b) allow the reaction to occur under reflux conditions; then (c) lower the temperature to 0-20° C.; (d) obtain the resultant ligand polymer by filtration; then (e) dry the obtained polymer; and (f) weigh the dried polymer; step 3 (a) add the dried ligand polymer and a solvent of twice the mass of the polymer to a reaction flask; (b) add a reducing agent to the reaction flask; (c) raise the temperature to 80-140° C.; and (d) reflux for 4-6 hours; step 4 (a) add a zirconium compound to the system in step 3, after the system reaches swelling equilibrium, wherein the zirconium compound is selected from the group consisting of zirconium hydroxide, zirconyl chloride octahydrate, zirconium dioxide, zirconium tetrachloride, zirconium(IV) acetylacetonate, zirconium trifluoroacetylacetonate, n-propyl zirconate, zirconium(IV) tert-butoxide, zirconium(IV) hydrogenphosphate and zirconium(IV) bromide; (b) raise the temperature to 80-100° C.; (c) react at the temperature of 80-100° C. for 2-4 hours, then (d) obtain a polymerization catalyst solution; wherein a reaction equation is as follows: ##STR00003## wherein n is a degree of polymerization and Zr—R is the zirconium compound.

2. The preparation method for S-indoxacarb according to claim 1, comprising the steps of: adding tert-butyl hydroperoxide and 5-chloro-2-methoxycarbonyl-1-indanone ester to the polymerization catalyst solution obtained by the method of claim 1 to carry out asymmetric synthesis, wherein a mole ratio of 5-chloro-2-methoxycarbonyl-1-indanone ester:tert-butyl hydroperoxide:catalyst is 1:1.2-1.5:0.05-0.1; raising the temperature to 60-120° C. for reflux reaction for 4 hours, filtering the obtained mixture to recover polymer catalyst, the key intermediate 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone is obtained by vacuum distillation of the filtrate, then, putting the recovered catalyst into toluene solvent to form suspension to continue to participate in the asymmetric synthesis reaction; after obtaining the above-mentioned 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone, making it react with carbobenzoxyhydrazide and diethoxymethane and finally, with hydrogenating deprotection, synthesizing S-indoxacarb with 4-trifluoromethoxy phenyl carbamate.

3. The preparation method for S-indoxacarb according to claim 1, wherein a mole ratio of 3-tert-butyl-5-(chloromethyl)salicylaldehyde to chiral cyclohexanediamine is 1:1-1.5, an amount of the solvent is 4-6 times of the mass of 3-tert-butyl-5-(chloromethyl)salicylaldehyde; the solvent is selected from the group consisting of methanol, ethanol, dichloromethane and dichloroethane.

4. The preparation method for S-indoxacarb according to claim 3, wherein the solvent is methanol.

5. The preparation method for S-indoxacarb according to claim 1, wherein the solvent in step (3) is selected from the group consisting of toluene, xylene, dichloroethane, n-hexane and tert butanol; and the reducing agent is selected from the group consisting of sodium borohydride, potassium borohydride and lithium aluminum hydride, and a mole ratio of the reducing agent used in step 3 to 3-tert-butyl-5-(chloromethyl)salicylaldehyde used in step 1 is 1-1.2:1.

6. The preparation method for S-indoxacarb according to claim 5, wherein the solvent in step (3) is toluene.

7. The preparation method for S-indoxacarb according to claim 1, wherein a mole ratio of the zirconium compound used in step 4 to 3-tert-butyl-5-(chloromethyl)salicylaldehyde used in step 1 is 1:1-2.

8. The preparation method for S-indoxacarb according to claim 7, wherein the zirconium compound in step (4) is zirconium(IV) acetylacetonate.

Description

SPECIFIC EMBODIMENTS

Embodiment 1: A Chiral Catalyst Containing Zirconium and a Preparation Method for S-Indoxacarb by Using this Catalyst

(1) The preparation method is as follows:

(2) (1) Add 22.65 g (0.1 mol) of 3-tert-butyl-5-(chloromethyl)salicylaldehyde to a 100 ml clean and anhydrous reaction flask, then add 50 ml of methanol, and then weigh 11.4 g (0.1 mol) of cyclohexanediamine and add it slowly at 20-25° C.

(3) (2) After adding, raise the temperature to 65-70° C. for reflux reaction. After the reaction, lower the temperature to 10° C., and a ligand polymer is obtained after filtration, then weigh the ligand polymer after drying.

(4) (3) Put the ligand polymer obtained in step (2) into a 2000 ml clean and anhydrous reaction flask, then add 50 ml toluene and 3.78 g (0.1 mol) sodium borohydride. Raise the temperature for the reflux reaction.

(5) (4) Add 24.35 g (0.05 mol) of zirconium(IV) acetylacetonate to the above said reaction system. Raise the temperature to 80° C. after being fully soaked. The toluene solution of the polymerization catalyst is obtained through heat preservation reaction.

(6) The method for preparing the S-indoxacarb by using the above said catalyst can adopt the conventional synthesis route disclosed in the paper “study on synthesis process of novel chiral insecticide indoxacarb and its polymorphism”, with which a master's degree was awarded by Zhejiang University in 2014. Wherein:

(7) (5) Add 225 g of tert-butyl hydroperoxide, 449 g of 5-chloro-2-methoxycarbonyl-1-indanone ester and 1000 mL of toluene to the catalyst toluene solution obtained in the above step (4) to carry out asymmetric synthesis reaction. Raise the temperature to 110° C. for the reflux reaction for 4 hours; after completion of the reaction, filter it to get the metal polymer catalyst. The key intermediate 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone can be obtained by vacuum distillation of the filtrate. Put the recovered catalyst into 50 ml toluene solvent to form suspension to continue to participate in the asymmetric synthesis reaction.

(8) (6) The key intermediate 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone which is obtained in the above step (5) reacts with carbobenzoxyhydrazide and diethoxymethane according to the conventional synthesis route shown in the description. And finally, with hydrogenating deprotection, synthesize S-indoxacarb with 4-trifluoromethoxy phenyl carbamate. The testing result of the content of S-enantiomer is 98.6%.

Embodiment 2: A Chiral Catalyst Containing Zirconium and a Preparation Method for S-Indoxacarb by Using this Catalyst

(9) The preparation method is as follows:

(10) (1) Add 22.65 g (0.1 mol) of 3-tert-butyl-5-(chloromethyl)salicylaldehyde to a 100 ml clean and anhydrous reaction flask, then add 50 ml of methanol, and then weigh 17.1 g (0.15 mol) of cyclohexanediamine and add it slowly at 20-25° C.

(11) (2) After adding, raise the temperature to 65-70° C. for reflux reaction. After the reaction, lower the temperature to 10° C., and a ligand polymer is obtained after filtration, then weigh the ligand polymer after drying.

(12) (3) Put the ligand polymer obtained in step (2) into a 2000 ml clean and anhydrous reaction flask, then add 50 ml toluene and 5.4 g (0.1 mol) potassium borohydride. Raise the temperature for the reflux reaction.

(13) (4) Add 24.35 g (0.05 mol) of zirconium(IV) acetylacetonate to the above said reaction system. Raise the temperature to 80° C. after being fully swelling. The toluene solution of the polymerization catalyst is obtained through heat preservation reaction.

(14) The method for preparing the S-indoxacarb by using the above said catalyst can adopt the conventional synthesis route disclosed in the paper “study on synthesis process of novel chiral insecticide indoxacarb and its polymorphism”, with which a master's degree was awarded by Zhejiang University in 2014. Wherein:

(15) (5) Add 113 g of tert-butyl hydroperoxide, 224 g of 5-chloro-2-methoxycarbonyl-1-indanone ester and 1200 mL of toluene to the catalyst toluene solution obtained in the above step (4) to carry out asymmetric synthesis reaction. Raise the temperature to 110° C. for the reflux reaction for 4 hours; after completion of the reaction, filter it to get the metal polymer catalyst. The key intermediate 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone can be obtained by vacuum distillation of the filtrate. Put the recovered catalyst into 50 ml toluene solvent to form suspension to continue to participate in the asymmetric synthesis reaction.

(16) (6) The key intermediate 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone which is obtained in the above step (5) reacts with carbobenzoxyhydrazide and diethoxymethane according to the conventional synthesis route shown in the description. And finally, with hydrogenating deprotection, synthesize S-indoxacarb with 4-trifluoromethoxy phenyl carbamate. The testing result of the content of S-enantiomer is 98.9%.

Embodiment 3: Recycling and Utilization of the Metal Polymer Catalyst

(17) Add the catalyst recovered from filtration in Embodiment 2 to toluene; then add 113 g of tert-butyl hydroperoxide, 224 g of 5-chloro-2-methoxycarbonyl-1-indanone ester and 1200 mL of toluene to carry out asymmetric synthesis reaction. Raise the temperature to 110° C. for the reflux reaction for 4 hours; after completion of the reaction, filter it to get the metal polymer catalyst. The key intermediate 5-chloro-2-methoxycarbonyl-2-hydroxy-1-indanone can be obtained by vacuum distillation of the filtrate. Put the recovered catalyst into 50 ml toluene solvent to form suspension to continue to participate in the asymmetric synthesis reaction; the obtained intermediate is prepared according to the conventional prior art to obtain S-indoxacarb.

(18) The results of the correlative experiments such as reuse times, reaction yield and the content of S-enantiomer are as follows:

(19) TABLE-US-00001 The content of Serial Yield S-enantiomer number (%) (%) Remarks 1 58.1 98.9 the first time for reuse 2 57.9 98.8 the second time for reuse 3 57.8 98.7 the third time for reuse 4 57.7 98.5 the fourth time for reuse 5 57.5 98.2 the fifth time for reuse 6 57.4 97.8 the sixth time for reuse 7 57.3 97.3 the seventh time for reuse 8 57.1 96.9 the eighth time for reuse 9 57 96.4 the ninth time for reuse 10 56.6 96 the tenth time for reuse

(20) It can be seen that the catalyst structure provided by this invention is stable, and is not easy to be lost during the reaction. The small experiments verify that the content of the S-enantiomer of the indoxacarb obtained after reusing ten times is still higher than the production level of DuPont (the content of the S-enantiomer: 90%). Cost accounting according to ten times of the catalyst reuse, the cost of using the catalyst is reduced more than RMB 30,000 compared with that of DuPont, which has greater economic and environmental benefits.

(21) In conclusion, it can be seen that the catalyst provided by this invention improves the selectivity during asymmetric synthesis, and the S-enantiomer content is increased from 75% to more than 98%. Among them, the preparation of the chiral catalyst introduced metal zirconium compounds, which greatly improved the reaction rate of asymmetric reactions. The reaction time has been shortened from 24 hours to 4 hours. At the same time, it is equipped with chiral diamine ligands and the selectivity in the asymmetric synthesis process is increased.