Phenacyl bromide → Ethyl 4-phenyl-1,3-thiazole-2-carboxylate

Participants

Reaction Steps

A mixture of 2-bromo-1-phenylethanone (1.790 g, 8.99 mmol) and ethyl 2-amino-2-thioxoacetate (Example 4A, 1.20 g, 9.01 mmol) in benzene (80 mL) and ethanol (10 mL) was stirred at room temperature for 18 h. The mixture was heated at 80° C. for 1 h. The solvent was evaporated under reduced pressure and the residue was partitioned between ethyl acetate (300 mL) and saturated aqueous sodium bicarbonate (100 mL). The organic phase was washed with brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The residual clear oil was chromatographed on silica gel (4×10 cm, elution toluene-ethyl acetate 0-2-4%) and gave a yellow oil (1.588 g). This was distilled in vacuo (bp: 105-115° C./0.1 torr, bulb to bulb distillation, air bath temperature) to provide the title material (1.409 g, 67%) as a pale yellow syrup which solidified to an almost colorless solid upon standing. LC (Method C): 2.009 min. HRMS (ESI) calcd for C12H12NO2S [M+H]+ m/z 234.0583, found 234.0597. 1H NMR (CDCl3, 400 MHz) δ ppm: 1.48 (t, J=7.2 Hz, 3H), 4.52 (q, J=17.2 Hz, 2H), 735-7.49 (m, 3H), 7.75 (s, 1H), 7.93-8.00 (m, 2H).

Provenance & Evidence