Benzoin acetate → Oxazole, 2-methyl-4,5-diphenyl-

Participants

Reaction Conditions

Reaction Steps

2-Oxo-1,2-diphenylethyl acetate 24 (0.20 g, 0.79 mmol) was dissolved in DMF (10 mL). Thiourea was then added and the reaction was refluxed (160° C., oil bath) under nitrogen atmosphere. As the reaction progressed, the color changed from colorless to a light yellow-orange and had an odorous smell. The reaction was monitored by TLC and when complete, the reaction mixture was dissolved in dichloromethane (40 mL) and then washed with water (3×30 mL). The dichloromethane layer was separated and dried over anhydrous sodium sulfate. Removal of the drying agent by filtration and rotary evaporation of the solvent gave a crude oil that was purified by flash chromatography on silica gel (dichloromethane) to provide 25 (74%): Rf: 0.098 (hexane/ethyl acetate, 2:1); FTIR 2920.50; 1220.30; 1502.00, 1588.24 cm−1; 1H NMR (400 MHz, CDCl3) δ: 2.617 (s, 3H); 7.25-7.66 (m, 10H, aromatic); 13C NMR (100 MHz, CDCl3) δ 160.35, 145.41, 134.82, 126.46-132.14, 13.92; HRMS calcd for C16H13NO (M+H)+ 236.1075, Found: 236.1077.

Provenance & Evidence