Hexamethylphosphoramide → Methyl 1-benzyl-7-methyl-2-oxoazepane-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of lithium diisopropylamide in THF (1.8 M, 10 mL, 18 mmol, 1.3 equiv) freshly prepared at −78° C. was added a solution of 1-benzyl-7-methylazepan-2-one (2-3, 3.8 g, 18 mmol, 1.0 equiv) in THF (10 mL) was added. The reaction mixture was warmed to 0° C. and stirred for 1 h, then cooled to −78° C. HMPA (3.0 mL, 17 mmol, 0.99 equiv) was added followed by methyl cyanoformate (1.8 mL, 23 mmol, 1.3 equiv). After stirring 10 minutes at −78° C. the mixture was partitioned between water (40 mL) and diethyl ether (2×40 mL). The combined organic extracts were dried over sodium sulfate and concentrated. The residue was purified by silica gel chromatography (0-100% ethyl acetate/hexanes gradient) to yield methyl 1-benzyl-7-methyl-2-oxoazepane-3-carboxylate (2-4). LRMS m/z (M+H) 276.2 found, 276.2 required.

Provenance & Evidence