3-[(2,2-Dimethyl-1-oxobutyl)thio]propanoic acid methyl ester synthesis

Yield: 98.4%

Reaction Conditions:

Stage #1:Methyl 3-mercaptopropionate;2,2-dimethylbutanoyl chloride in dichloromethane at 10; for 0.25 h;
Stage #2: with ammonia in dichloromethane; pH=7 at 0 - 65; for 1.8 h;Time;Solvent;

Steps:

1 Example 1
To the reaction vessel was added 40g of 2,2-dimethyl butyryl chloride, and then to the reaction vessel was added dropwise 250ml of dichloromethane, stirred for 15min,After the end of the stirring to the outer jacket of the reactor by adding 15% ice brine cooling cooling treatment, when the temperature in the reaction vessel was cooled to 10 ° C, the reaction vessel was added 25g of 3-mercapto propionic acid, stirring was continued The temperature is lowered so that 2,2-dimethylbutyryl chloride reacts with 3-mercaptopropionate A to produce methyl α-dimethylbutyryl-S-propionate and hydrogen chloride.When the material in the reaction kettle was cooled to 0 ° C, ammonia gas was introduced into the reaction vessel until the pH in the reaction vessel was 7,Ammonia was stopped, heated to 65 ° C and held for 1.8 h,So that ammonia and hydrogen chloride generated by the reaction, ammonium chloride generated to promote the progress of the reaction until the reaction is completed, the reaction vessel was added 100ml of water,After the addition and stirring 30min, making the reaction of hydrogen chloride fully dissolved in water, and then allowed to stand 4.5h, making the dissolved liquid layering.After the liquid is layered, an aqueous layer and an organic layer are obtained, and the aqueous layer is an aqueous solution of ammonium chloride. The aqueous layer of the aqueous layer is directly transferred or collected by an iron drum to recover the ammonium chloride, and the methylene chloride is recovered by distillation to obtain 55 g Of the crude product, and the recovered methylene chloride solution was recycled,55 g of the crude product was dissolved by heating in 300 ml of ethanol, decolored with activated charcoal, concentrated to 5 ° C and held for 2 h to give 52 g of a mixture, 52 g of the mixture was filtered and washed with 78 g of methylene chloride and finally 48.8 g of product was obtained by drying. The yield of methyl α-dimethylbutyryl-S-propionate was 98.4% with a purity of more than 99.0%.

References:

Quzhou Xinbu Chemical Technology Co., Ltd.;Yan Zhaochun CN105837482, 2016, A Location in patent:Paragraph 0031-0034; 0036-0038; 0040-0042; 0044-0046