938063-63-9

2935-90-2

5856-77-9

938063-63-9

To the reaction vessel was added 40 g of 2,2-dimethylbutyryl chloride followed by dropwise addition of 250 ml of dichloromethane and stirred for 15 minutes. After stirring was completed, 15% ice brine was added to the reactor jacket for cooling treatment. When the temperature in the reaction vessel was reduced to 10 °C, 25 g of methyl 3-mercaptopropionate was added and stirring was continued. The temperature was further reduced to induce the reaction of 2,2-dimethylbutyryl chloride with methyl 3-mercaptopropionate to form methyl 3-[(2,2-dimethyl-1-oxobutyl)thio]propionate and hydrogen chloride. When the temperature of the substance in the reaction vessel was reduced to 0°C, ammonia was passed into the reaction vessel until the pH of the reaction system reached 7, and the passage of ammonia was stopped. The reaction mixture was then heated to 65°C and maintained for 1.8 hours to allow the ammonia to react with the hydrogen chloride to form ammonium chloride, thereby promoting completion of the reaction. Upon completion of the reaction, 100 ml of water was added to the reaction vessel and stirred for 30 minutes to ensure that the hydrogen chloride was fully dissolved in water. Afterwards, it was left to stand for 4.5 hours to stratify the liquid. After layering, the aqueous and organic layers were separated and the aqueous layer was an aqueous solution of ammonium chloride. The aqueous layer can be directly transferred or collected to recover the ammonium chloride. Recovery of dichloromethane by distillation gave 55 g of crude product. The crude product was dissolved in 300 ml of ethanol, heated to dissolve and decolorized with activated carbon. The solution was then concentrated and kept at 5°C for 2 hours to give 52 g of the mixture. The mixture was filtered and washed with 78 g of dichloromethane and dried to give a final product of 48.8 g of methyl 3-[(2,2-dimethyl-1-oxobutyl)thio]propionate in 98.4% yield and >99.0% purity.