Dimethyl Sulfoxide → 1,1-Dimethylethyl 4-(3-{6-[(2,2-dimethylpropanoyl)amino]-2-fluoro-3-pyridinyl}-3-oxopropyl)-1-piperidinecarboxylate

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Reaction Steps

To a solution of oxalyl chloride (0.11 ml, 1.25 mmol) in dichloromethane (10 ml) was added dropwise dimethylsulfoxide (0.18 ml, 2.51 mmol) at −78° C. After stirring for 10 min, a solution of 1,1-dimethylethyl 4-(3-{6-[(2,2-dimethylpropanoyl)amino]-2-fluoro-3-pyridinyl}-3-hydroxypropyl)-1-piperidinecarboxylate (step 1, 500 mg, 1.14 mmol) in dichloromethane (5 ml) was added to the mixture at −78° C. After 15 min, triethylamine (0.79 ml, 5.70 mmol) was added at the same temperature and the resulting mixture was allowed to warm up to room temperature and stirred for 18 h. The mixture was quenched with 1N aqueous hydrochloric acid (100 ml) and extracted with dichloromethane (150 ml). The organic layer was washed with water (50 ml) and dried over magnesium sulfate. Removal of solvent gave a pale yellow solid, which was chromatographed on a column of silica gel eluting with ethyl acetate/hexane (4:1 ) to afford 362 mg (73%) of the title compound as a white solid.

Provenance & Evidence