反应详情

5.0 g (51.0 mmol) of maleic anhydride were heated to 100° C. in 2.2 ml of MeOH for 1 hour [J. Chem. Soc., 1964, 526-528]. The reaction mixture was cooled to room temperature and 37 ml (50.7 mmol) of SOCl2 were added dropwise. The reaction was refluxed for 1.5 hours and then distilled collecting the fraction boiling at 42-44° C./2 mbar to obtain 5.3 g of the title compound, possibly as a mixture of E and Z diastereoisomers. This compound was used without further purification in the subsequent reaction to prepare Examples 18 and 19.

1. temperatureThe reaction was refluxed for 1.5 hours
2. distillationdistilled
3. customcollecting the fraction boiling at 42-44° C./2 mbar