Water → Methyl 5-[4-(difluoromethoxy)phenyl]-1-[(1,1-dioxidothiomorpholin-4-yl)carbonyl]piperidine-3-carboxylate

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Reaction Steps

2.2 g (7.7 mmol) of methyl 5-[4-(difluoromethoxy)phenyl]piperidine-3-carboxylate were dissolved in 14 ml of N-methylpyrrolidone, and admixed with 4.0 ml (3.0 g, 23.0 mmol) of N,N-diisopropylethylamine and 3.5 g (11.5 mmol) of 4-nitrophenyl thiomorpholine-4-carboxylate 1,1-dioxide. The reaction mixture was converted in a microwave at 180° C. for seven minutes. Subsequently, water and ethyl acetate were added, and the aqueous phase was removed and extracted repeatedly with ethyl acetate. The combined organic extracts were washed with water and saturated aqueous sodium chloride solution, dried over sodium sulphate, filtered and concentrated under reduced pressure. The residue was taken up in diethyl ether and filtered, and the filtrate was purified by means of preparative HPLC. Yield: 2.0 g (51% of theory)

Provenance & Evidence