Chloroacetaldehyde → HCID 89793959, compound

Participants

Reaction Conditions

Reaction Steps

(R)-tert-butyl 4-((tert-butoxycarbonyl)amino)-3-oxohexanoate (505a, 7.41 g, 24.59 mmol) was treated with ammonia (2M in MeOH, 123 mL, 246 mmol) and ammonium acetate (14.21 g, 184 mmol) at RT. The resulting mixture was stirred for at 50° C. for 30 min, then treated with chloroacetaldehyde (50 wt % in water, 15.82 mL, 123 mmol) and stirred at 50° C. for 2 h. The reaction mixture was then stirred at RT overnight. The reaction mixture was concentrated to remove most of MeOH and partitioned between sat'd NaHCO3 (100 mL) and EtOAc (100 mL). The aqueous layer was extracted with EtOAc (2×50 mL), and the combined organics were washed with water and brine, dried over anhydrous MgSO4, filtered, and concentrated in vacuo to give a brown residue. It was purified on an ISCO Combiflash RF (160 g Thomson SingleStep column, 0-10% EtOAc in DCM) affording (R)-tert-butyl 2-(1-((tert-butoxycarbonyl)amino)propyl)-1H-pyrrole-3-carboxylate (505b, 4.58 g, 14.12 mmol, 57.4% yield) as a light yellow viscous oil. m/z (ESI, +ve) 347.1 (M+Na)+

Provenance & Evidence