1. Preparation of Drug Articaine Hydrochloride
36-39mol methyl thioglycolate and 2-5L (37-40mol) 2-methacrylonitrile were reacted in a mixed solution of 11-14L sodium methoxide and methanol (prepared from metal sodium 0.8-1.1kg), after the reaction was over Adjust pH value with concentrated hydrochloric acid to be 7 and add dropwise 30% hydrogen peroxide 4-7L (4-7mol), then add concentrated hydrochloric acid 3.5L dropwise to the reaction system, concentrate under reduced pressure to obtain intermediate compound B; 3-5kg (18-21mol) Intermediate compound B was dissolved in 25L dichloromethane containing 4-6L (55-58mol) pyridine, and α-chloropropionyl chloride 3-5L (37-40mol) was added dropwise. After the reaction, the reaction mixture was After washing, drying and concentration under reduced pressure, intermediate compound C was obtained. 2-4kg (10-13mol) of intermediate compound C was dissolved in 3-6L dimethyl sulfoxide and added dropwise to the solution containing 1-3L (24-279mol) n-propylamine and In the solution of 21-40L dimethyl sulfoxide, after the reaction is completed, mix with ice water, extract with ethyl acetate, dry, and concentrate under reduced pressure to obtain an oily substance, then dissolve the oily substance with acetone, and adjust the pH value with concentrated hydrochloric acid. 5-6, crystallize, filter, and dry to obtain crude articaine hydrochloride.
2. Hair care and depilatory in tanning
Methyl thioglycolate can effectively attack the connective tissue connected to the hair root, more effective hair removal, and keep the hair intact in the liming solution. The steps of tanning for hair protection and depilation are as follows:
(1) Soaking in water: Weigh 100 parts by weight of raw hides and put them in a rotating drum, add 200 parts by weight of clear water, 0.15 parts by weight of water immersion aids, and 0.2 parts by weight of preservatives, turn at 28°C for 4 hours; add 0.2 parts of soda ash, Continue to rotate for 6 hours; drum out and wipe off the moisture on the surface of the skin;
(2) Hair protection and depilation: take 100 parts by weight of the above-mentioned treated rawhide in a drum, add 100 parts by weight of water, 0.1 part by weight of a hair-preserving and depilatory agent, rotate at 28°C for 15 minutes, stop for 15 minutes, repeat 5 times; add 0.1 parts by weight of sodium sulfide and turn for 4 hours, separate and remove hair;
(3) Lime: Continue to add 100 parts by weight of water, 2.0 parts by weight of hydrated lime, 1.0 parts by weight of liming aids, 0.2 parts by weight of preservatives, turn at 28°C for 60 minutes, stop and soak for 60 minutes, and then continue to turn 10 minutes, stop and soak for 60 minutes, a total of 8 hours; drum;
(4) Washing: Weigh 100 parts by weight of the above-mentioned treated ash skin into a drum, add 100 parts by weight of water, 0.2 parts by weight of water washing aid, rotate at 28°C for 30-60 minutes, and eject the drum. The soaking aid is sodium lauryl sulfate with a weight ratio of 1:0.5: nonylphenol polyoxyethylene; polyoxypropylene ether; the hair-preserving and depilatory agent is methyl thioglycolate; the liming aid is chitosan; The agent is dodecyl polyoxyethylene phosphate.
3. Preparation of non-steroidal anti-inflammatory drug intermediates
After chlorination, acrylonitrile reacts with methyl thioglycolate under the protection of N2 atmosphere in sodium methoxide to obtain 2-carboxymethyl-3-aminothiophene, the amino group is replaced by a sulfonyl chloride group and then chlorinated, and reacts with methylamine to obtain 5-carboxymethyl-3-aminothiophene. Methyl chloro-2-carboxylate-3-methylaminosulfonylthiophene. Methyl 5-chloro-2-carboxylate-3-methylaminosulfonylthiophene (MCMTC) is an important intermediate of non-steroidal anti-inflammatory drugs, which can synthesize lornoxicam, tenoxicam and other anti-inflammatory drugs. Blood lipids and drugs for the treatment of rheumatism.
