Hydrochloric Acid → (2-Ethylthiazol-4-yl)(1-oxa-4,9-diazaspiro[5.5]undecan-4-yl)methanone

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-(2-ethylthiazole-4-carbonyl)-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate (limiting reagent) (step a) in iPrOH (3 volumes) was added hydrogen chloride (2 molar equivalents of a 5-6N solution in iPrOH). The reaction mixture was heated and stirred at 49° C. (internal) for 18 hr before being cooled to 22° C. TBME (4.3 volumes) was added and the suspension was stirred at 22° C. for 3 days. The solid was collected by filtration, washed with TBME (3.5 volumes) and air dried for 2 days to give an off white solid. Yield 95% of theoretical.

Provenance & Evidence