Dichloroacetic Acid → HCID 58550801, compound

Participants

Reaction Steps

To 2-(3-methylpyrrol-1-yl)phenol (2.0 g, 12 mmol) and tert-butyl 4-oxopiperidine-1-carboxylate (2.5 g, 13 mmol) in dichloromethane (36 mL) under N2 was added, dropwise at 0° C., dichloroacetic acid (1.9 mL, 23 mmol) over 5 min. The mixture was stirred at that temperature for 2 h then held at 5° C. overnight. The mixture was washed with water (10 mL), 1M NaOH (20 mL) and brine (10 mL), dried over MgSO4 and purified by column chromatography (0-30% EtOAc/hexane) to give a mixture of product isomers (˜2.7 g, 68%, 2:1 ratio by NMR). The mixture was subjected to SFC separation using ChiralPak OD-H (30% MeOH w/0.1% DEA, 70% CO2) to give tert-butyl 3-methylspiro[benzo[b]pyrrolo[1,2-d][1,4]oxazine-4,4′-piperidine]-1′-carboxylate as the first eluting fraction (1.0 g, 37%) and tert-butyl 2′-methylspiro[piperidine-4,4′-pyrrolo[2,1-c][1,4]benzoxazine]-1-carboxylate as the second eluting fraction (0.40 g, 30%).

Provenance & Evidence