Dichloromethane → 4-[5-(4-(cyclopropylsulphonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

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Reaction Steps

10 g of 4-(5-(piperazin-1-yl)pyridin-2-yl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester are placed in a 500 ml round-bottomed flask. 126 ml of dichloromethane are added, followed by 4.23 ml of triethylamine and, finally, 2.7 ml of cyclopropylsulphonyl chloride. The reaction mixture is stirred at ambient temperature for 16 h, then washed with water and once with a saturated sodium chloride solution, dried over magnesium sulphate and then evaporated under reduced pressure. The crude product obtained is chromatographed on silica gel, elution being carried out with a gradient of methanol in dichloromethane varying from 0% to 10%. 10.9 g of 4-[5-(4-(cyclopropylsulphonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester are obtained.

Provenance & Evidence