[CH3:1][C:2]1[O:3][C:4](=[O:8])[O:5][C:6]=1[CH3:7].S(Cl)([Cl:12])(=O)=O>C(Cl)Cl>[Cl:12][C:2]1([CH3:1])[C:6](=[CH2:7])[O:5][C:4](=[O:8])[O:3]1To a solution of 75 g of 4,5-dimethyl-1,3-dioxolene-2-one (IV) in 750 ml of methylene chloride was added 97.6 g of sulfuryl chloride dropwise at 40°-42° C. over 2 hours. The mixture was stirred for 40 minutes at the same temperature and evaporated in vacuo to remove the solvent. NMR spectrometry of the resulting oil revealed that the product was 4-chloro-4-methyl-5-methylene-1,3-dioxolane-2-one (III) containing a trace amount of unreacted 4,5-dimethyl-1,3-dioxolene-2-one (IV). This oil was heated at 90° C. with stirring for 2 hours without isolating 4-chloro-4-methyl-5-methylene-1,3-dioxolane-2-one (III) and then distilled in vacuo. 75.4 g (corresponding to an overall yield from 4,5-dimethyl-1,3-dioxolene-2-one (IV) of 77%) of 4-chloromethyl-5-methyl-1,3-dioxolene-2-one (II) having the physicochemical properties described in Reference Example 1 was obtained.
Wird geladen…