Benzyl Mercaptan CAS 100-53-8

α, β unsaturated ketenes are important skeletons in the field of organic synthesis, especially polysubstituted ketenes, which have important applications in organic synthesis. But so far, there are still few methods to synthesize polysubstituted enones with high selectivity. Allenes have attracted the research interest of scientists due to their biological activities in natural products and pharmaceuticals. Due to the presence of two accumulated double bonds in allenes, different reactivity from enynes can be exhibited.

Controlling the reaction selectivity of the two double bonds is currently the biggest challenge. Some studies provide a method for the efficient synthesis of α, β unsaturated iodoketenes and alkenals. Starting from allene sulfoxide, in a solvent with chloroform and ethanol as 50/1, the reaction with iodine and benzyl mercaptan can be used. It can generate iodoketene and alkenal compounds with high selectivity. The C I bond in these compounds can efficiently synthesize α, β unsaturated aldehydes and ketones through further coupling reaction. The synthesis reaction formula is as follows:

The preparation method is as follows:

1. Add 1.05 mmol of iodine to the mixed solution of 0.3 mmol of allene sulfoxide 1, 1 mL of chloroform, and 30 μL of ethanol, stir for 5 minutes, and then add the chloroform solution of benzyl mercaptan, the benzyl mercaptan 0.3 mmol , 0.5 mL of the chloroform, react for a certain time;
2. After the reaction of allene sulfoxide 1 is complete, add 6 mL of water to quench the reaction, then dropwise add saturated sodium thiosulfate solution to neutralize excess iodine, extract three times with 20 mL of ether, wash with saturated sodium chloride, no Dry with sodium sulfate, filter, and rotary steam to obtain liquid crude products. These crude products can be subjected to column chromatography to obtain clean iodoketene and alkenal compounds 2.

The preparation method is:

1. 4,5-dichlorophthalic anhydride and amine are refluxed in propionic acid at a molar ratio of 1:1.5-3 at 140-160° C. for 2-4 hours;
2. The product prepared in step A and benzyl mercaptan in a molar ratio of 1:2-3 in the presence of excess K2CO3 in dimethylacetamide at 60-80 DEG C for heating and reacting for 10-16 hours;
3. The product prepared in step B is debenzylated in dry toluene in the presence of excess AlCl3, reacted with carbonyldiimidazole at 70-90°C for 2-5 hours, 4,5-dibenzylthio-substituted phthalate The molar ratio of carboximide to carbonyldiimidazole is 1:1-3;
4. The product prepared in step C is refluxed in a toluene/triethyl phosphite mixed solution with a molar ratio of 2-3/1, and the self-coupling reaction is carried out for 10-14 hours, and the target product is obtained by cooling and filtration.

The preparation method is that alkyl xanthate and benzyl halide are subjected to esterification reaction to obtain benzyl alkyl xanthate; the benzyl alkyl xanthate is subjected to aminolysis reaction with aliphatic amine to obtain thiamine The mixture of ester and benzyl mercaptan; after the mixture of thiourethane and benzyl mercaptan is oxidized with hydrogen peroxide, the liquid-solid is separated, and the obtained solid is the dibenzyl disulfide product, and the obtained liquid is allowed to stand, and the oil and moisture layer, the oil phase is the thiourethane product.

The dibenzyl disulfide and thiourethane products obtained by the method have high yield and high purity, and the products are easy to separate in the preparation process, are environmentally friendly, have high atom economy, low production cost, and are easy to realize industrialized production.

Use dimethyl sulfoxide as the reaction solvent, use benzyl mercaptan and vinyl palmitate with a molar ratio of 1:0.5-6 as the raw material, use lipase Lipozyme-TL-IM as the catalyst, put the raw material and the reaction solvent in a syringe , the lipase Lipozyme-TL-IM is uniformly filled in the reaction channel of the microfluidic channel reactor, and the raw material and reaction solvent are continuously passed into the reaction channel device under the driving of the syringe pump to carry out the acylation reaction. The inner diameter of the reaction channel of the channel-controlled reactor is 0.8-2.4mm, and the length of the reaction channel is 0.5-1.0m; the acylation reaction temperature is controlled to be 20-60°C, and the acylation reaction time is 20-40min, and the reaction is collected online through a product collector. The reaction solution is subjected to conventional post-treatment to obtain S-benzyl palmitic acid thioester.

The present invention has the advantages of short reaction time, high selectivity and high yield.

The synthesis of thioester compounds generally adopts esterification method, and this method mainly uses strong acids such as sulfuric acid and benzenesulfonic acid as catalysts. Another report adopts trifluoromethanesulfonate or transition metal to catalyze the preparation of thioester compounds. Such reactions have transition metal complexes that are difficult to prepare, expensive, easy to run off, difficult to recycle, and produce substances that are harmful to the environment. shortcoming. With the increasingly prominent problem of environmental pollution, it is urgent to develop green and efficient synthesis methods that are less harmful to human health and the environment.

In some studies, dimethyl sulfoxide was used as the reaction solvent, benzyl mercaptan and vinyl acetate with a substance ratio of 1:0.5 to 6 were used as raw materials, and lipase Lipozyme-TL-IM was used as a catalyst. Put it in a syringe, evenly fill the lipase Lipozyme-TL-IM in the reaction channel of the microfluidic channel reactor, and under the push of the syringe pump, the raw materials and the reaction solvent are continuously passed into the reaction channel device to carry out the acylation reaction, The inner diameter of the reaction channel of the microfluidic channel reactor is 0.8 to 2.4 mm, and the length of the reaction channel is 0.5 to 1.0 m; the acylation reaction temperature is controlled to be 20 to 60° C., and the acylation reaction time is 20 to 40 minutes. The reaction solution was collected online with a device, and the reaction solution was subjected to conventional post-treatment to obtain S-thioacetate benzyl ester.