Diisopropylethylamine → tert-Butyl 1-((2R)-3-(benzyloxy)-1-(2-methyl-1-oxo-4-phenyl-2,7-diazaspiro[4.5]decan-7-yl)-1-oxopropan-2-ylamino)-2-methyl-1-oxopropan-2-ylcarbamate

Participants

Reaction Steps

A mixture comprising (R)-3-(benzyloxy)-2-(2-(tert-butoxycarbonylamino)-2-methyl propanamido)propanoic acid (Intermediate 3A) (800 mg, 2.103 mmol) and a racemic mixture of (4R,5S)-2-Methyl-4-phenyl-2,7-diazaspiro[4.5]decan-1-one and (4S,5R)-2-Methyl-4-phenyl-2,7-diazaspiro[4.5]decan-1-one (Intermediate 1A) (514 mg, 2.103 mmol) in DMF (10 ml) was treated with DIPEA (1.102 ml, 6.31 mmol) and ®T3P (amide coupling agent 50% in DMF, 2.455 ml, 4.21 mmol) and stirred at RT for 1 hour. The resulting mixture was concentrated in vacuo and the residue was suspended in water (50 ml) and extracted with EtOAc (2×100 ml). The combined organic extracts were dried (MgSO4) and concentrated in vacuo. Purification by chromatography on silica eluting with 0-100% EtOAc in iso-hexane afforded the title compound as a white foam.

Provenance & Evidence