tert-butyl N-(2-(methoxy(methyl)carbamoyl)ethyl)carbamate → 3-Amino-1-{1-[1-(1-phenylcycloheptyl)-4-piperidinyl]-1H-benzimidazol-2-yl}-1-propanone

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-[1-(1-phenylcycloheptyl)-4-piperidinyl]-1H-benzimidazole (Example 12, 66.3 mg, 0.178 mmol) in THF(4 ml) was added n-butyllithium (1.54M solution in hexane, 0.923 ml, 1.42 mmol) at −78° C. After 1 h stirring at −78° C., a solution of 3-t-butoxycarbonylamino-N-methoxy-N-methylpropionamide (140 mg, 0.604 mmol, this was prepared according to the reported procedure: G. Bitan et al, J. Chem. Soc., Perkin Trans. 1, 1997, 1501-1510) in THF (1.5 ml) was added to the reaction mixture at −78° C. After 0.5 h stirring at −78° C. and 15 h stirring at ambient temperature, the reaction mixture was quenched with water and extracted with ethyl acetate. The extracts combined were washed with brine, dried (Na2SO4), filtered, and concentrated. The residue was purified by preparative TLC (1 mm plate×3, n-hexane/acetone: 5/1, 6 times developed) to give 71.7 mg (74%) of pale brown amorphous solid. This solid (70 mg, 0.131 mmol) was dissolved in HCl solution in MeOH (10 ml). After evaporation of the solvent, the residue was dried in vacuo at 45° C. for 18 h to afford 60 mg (89%) of pale brown amorphous solid.

Provenance & Evidence