反应详情

A solution of 3-hydroxy-2-(3-methyl-1-oxo-2-buten-1-yl) thiophene (39.0 g, 0.214 mol) and p-toluenesulfonic acid (3.5 g, 18 mmol) in toluene (400 mL) was heated to reflux for 3.5 d. The resultant solution was washed with saturated aqueous sodium bicarbonate and dried over sodium sulfate. The solvent was evaporated in vacuo to give a brown oil, 38.62 g (99%). A portion of the resultant oil was purified for analysis by distillation in a Kugelrohr oven at 145° to 155° C. at 0.35 mm Hg to give the product as an amber oil: IR (neat): 2979, 1664, 1530 and 1442 cm-1 ; MS: m/z 183 (MH+); 1H NMR (CDCl3): δ1.51 (s, 6H); 2.67 (s, 2H); 6.67 (d, J=5.4 Hz, 1H) and 7.60 (d, J=5.4 Hz, 1H).

1. temperatureto reflux for 3.5 d
2. washThe resultant solution was washed with saturated aqueous sodium bicarbonate
3. dry with materialdried over sodium sulfate
4. customThe solvent was evaporated in vacuo
5. customto give a brown oil, 38.62 g (99%)
6. distillationA portion of the resultant oil was purified for analysis by distillation in a Kugelrohr oven at 145° to 155° C. at 0.35 mm Hg