Hydrochloric Acid → 4-[4-(4-Oxopiperidin-1-yl)phenyl]piperazine-1-carboxylic acid benzyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-[4-(1,4-dioxa-8-azaspiro[4.5]decan-8-yl)phenyl]piperazine-1-carboxylic acid benzyl ester (30 g) in 1,4-dioxane (450 ml) was added 1N-hydrochloric acid (240 ml) at ambient temperature, and the mixture was stirred for 7 hours at 90° C. The reaction mixture was poured into water. The mixture was adjusted to pH 10-12 with 1N-sodium hydroxide (480 ml), and extracted with ethyl acetate. The organic layer was washed with water, brine, and dried, and evaporated under reduced pressure. The residue was chromatographed on a column of silica gel eluting with dichloromethane/methyl alcohol (50:1) to give 4-[4-(4-oxopiperidin-1-yl)phenyl]piperazine-1-carboxylic acid benzyl ester (21.22 g).

Provenance & Evidence