Triethylamine → (3R)-3-[3-({[1-(tert-butoxycarbonyl)-3-azetidinyl]amino}carbonyl)-1,2,4-oxadiazol-5-yl]-6-cyclohexylhexanoic acid

Participants

Reaction Conditions

Reaction Steps

A solution of (3R)-6-cyclohexyl-3-[3-(ethoxycarbonyl)-1,2,4-oxadiazol-5-yl]hexanoic acid (Preparation 4) (480 mg, 1.42 mmol) and triethylamine (1 ml, 7.18 mmol) in ethanol (8 ml) was treated with tert-butyl 3-amino-1-azetidinecarboxylate (Preparation 78) (300 mg, 1.74 mmol) and the resulting mixture was heated at 80° C. under a nitrogen atmosphere for 18 hours. The solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel eluting with a gradient system of dichloromethane:methanol (99:1) gradually changing to dichloromethane:methanol (90:10) to afford the title compound contaminated with starting amine. The solid was dissolved in ethyl acetate and washed with hydrochloric acid (0.5M) (2×), water and brine, dried over magnesium sulphate, filtered and the solvent was removed under reduced pressure to afford the title compound as a sticky foam.

Provenance & Evidence