1-(2-(Tert-butoxycarbonylamino)-5-methoxyphenyl]-2-butanone → [2-(Tert-butoxycarbonylamino)-5-methoxyphenyl]cyclopropyl ketone

Participants

Reaction Conditions

Reaction Steps

1-[2-(tert-Butoxycarbonylamino)-5-methoxyphenyl]-2-butanone. A solution of 1.3M sec-butyl lithium/cyclohexane (100 mL, 0.13 mol) was added slowly to 15.17 g (0.065 mol) of N-tert-butoxycarbonyl-4-methoxy-2-methylaniline in 230 mL of THF while keeping the temperature below −40° C. with a dry ice-ethanol bath. The bath was removed and the temperature allowed to rise to −20° C. and then the bath was replaced. After the temperature had cooled to −55° C., 8.4 g (0.065 mol) of N-methoxy-N-methylcyclopropylcarboxamide in 20 mL of THF was added dropwise. The reaction mixture was stirred 1 hour, the cooling bath removed and stirred an additional 2 hours. It was then poured into 500 mL of water. The organic layer was separated, washed with water, dried over Na2SO4 and concentrated at reduced pressure. The residue was crystallized from hexane to give 15.22 g (77% yield) of [2-(tert-butoxycarbonylamino)-5-methoxyphenyl] cyclopropyl ketone, melting at 96-97° C.,

Provenance & Evidence