Dimethyl Sulfoxide → HCID 13192293, compound

Participants

Reaction Conditions

Reaction Steps

A solution of oxalyl chloride (3.5 ml, 40 mmol, 1.1 eq.) in dichloromethane (350 ml) was cooled to −60° C. (internal temp.) and treated drop-wise with dimethyl sulfoxide (5.18 ml, 73.0 mmol, 2 eq.). On completion of addition the reaction mixture was stirred at −60° C. for 5 min. before drop-wise addition of a solution of trans-benzyl-4-(2,3-dimethylphenoxy)-3-hydroxypiperidine-1-carboxylate (13.0 g, 36.5 mmol) in dichloromethane (50 ml). After 30 min. triethylamine (15.5 ml, 110 mmol, 3.0 eq.) was added drop-wise and the solution stirred at −60° C. for 10 min, before allowing the mixture to warm slowly to room temperature. After 18 h. the reaction mixture was diluted with water (400 ml) and the resultant biphasic system separated. The aqueous layer was extracted with dichloromethane (400 ml). Combined organics were washed with aqueous hydrochloric acid (200 ml, 0.1N), dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo to furnish benzyl 4-(2,3-dimethylphenoxy)-3-oxopiperidine-1-carboxylate as a pale yellow amorphous solid (12.8 g, 99%).

Provenance & Evidence