2-Bromo-1-(5-chloro-2-methoxyphenyl)ethanone → 5-[4-(5-Chloro-2-methoxy-phenyl)-oxazol-2-yl]-pentanoic acid methyl ester
Reaction equation
Br[CH2:2][C:3]([C:5]1[CH:10]=[C:9]([Cl:11])[CH:8]=[CH:7][C:6]=1[O:12][CH3:13])=O.[CH3:14][O:15][C:16](=[O:24])[CH2:17][CH2:18][CH2:19][CH2:20][C:21](=[O:23])[NH2:22]>CO>[CH3:14][O:15][C:16](=[O:24])[CH2:17][CH2:18][CH2:19][CH2:20][C:21]1[O:23][CH:2]=[C:3]([C:5]2[CH:10]=[C:9]([Cl:11])[CH:8]=[CH:7][C:6]=2[O:12][CH3:13])[N:22]=1Participants
4
Procedure
Combine 2-bromo-1-(5-chloro-2-methoxy-phenyl)-ethanone (12.0 g, 46 mmol) with 5-carbamoyl-pentanoic acid methyl ester (12.7 g, 79.9 mmol) and heat the neat mixture in a sealed vessel at 120-140° C. for about 6 h. Cool the mixture and add methanol and allow the mixture to stir overnight at room temperature. Concentrate the mixture and partition the residue between aq NaHCO3 and EtOAc. Dry the combined extracts over Na2SO4 and concentrate. Chromatography over silica gel (CHCl3) allows for recovery of 5-[4-(5-chloro-2-methoxy-phenyl)-oxazol-2-yl]-pentanoic acid methyl ester (5.5 g, 37%). MS (ES): (M+1)+ 324.1, 326.1 m/z.