1,3-Bis(benzyloxycarbonyl)-2-methylisothiourea → 1,1-dimethylethyl 7-[2-({[(phenylmethyl)oxy]carbonyl}amino)-1H-benzimidazol-6-yl]-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1,1-dimethylethyl 7-(3,4-diaminophenyl)-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (2.0 g, 5.6 mmol) in acetic acid (20 mL) was added 1,3-bis(benzyloxycarbonyl)-2-methyl-2-thiopseudourea (2.4 g, 6.7 mmol) and the resulting mixture was heated (60° C.). After 12 h the reaction mixture was partitioned between ethyl acetate (50 mL) and water (50 mL). The organic layer was then washed with brine (50 mL), dried over anhydrous magnesium sulfate, filtered and concentrated. Column chromatography on silica (0 to 50% ethyl acetate/hexanes) provided 1,1-dimethylethyl 7-[2-({[(phenylmethyl)oxy]carbonyl}amino)-1H-benzimidazol-6-yl]-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (1.3 g, 45% yield) as a brown solid. MS (EI) for C29H30N4O5: 515 (MH+).

Provenance & Evidence