131109-75-6

The general procedure for the synthesis of 1-(3-chloropyridin-2-yl)ethanone from methylmagnesium bromide and 3-chloro-2-cyanopyridine was as follows: to a mixture of 54 g of 3-chloro-2-cyanopyridine and 300 mL of tetrahydrofuran (THF) was added slowly and dropwise 500 g of 1 M methylmagnesium bromide in a THF solution under ice bath cooling conditions. Keeping the ice bath cool, the reaction mixture was stirred for 2 hours. Subsequently, the reaction mixture was slowly added to a 2 N hydrochloric acid solution under ice bath cooling and stirring was continued for 30 minutes. The pH of the mixture was adjusted to 8 with 1 N aqueous sodium hydroxide solution, after which it was extracted with ethyl acetate. The organic layer was washed with saturated brine and dried with anhydrous sodium sulfate. Finally, the organic layer was concentrated by decompression to give 58 g of intermediate (12-1).

[1] Patent: JP2017/36339, 2017, A. Location in patent: Paragraph 0178
[2] Patent: US2017/295787, 2017, A1. Location in patent: Paragraph 0639
[3] Patent: US2017/305896, 2017, A1. Location in patent: Paragraph 0621