Methyl 1-aminocyclohexanoate → Methyl 1-(3-((s)-1-tert-butoxycarbonyl-3-methylbutyl)ureido)cyclohexanecarboxylate

Participants

Reaction Steps

A solution of 28 g (179 mmol) of methyl 1-aminocyclohexane-1-carboxylate was added to a solution of 38 g (179 mmol) of L-leucine tert-butyl ester isocyanate (prepared analogously to J. S. Nowick et al., J. Org. Chem. 1996, 61, 3929) in 300 ml of absolute DMF. After stirring at room temperature for 2 hours, the reaction mixture was allowed to stand overnight. The solvent was removed in vacuo, the residue was treated with heptane and the mixture was stirred at room temperature for 2 hours. The precipitate was filtered off with suction and washed with heptane. Yield: 45.94 g (69%).

Provenance & Evidence