| 摘要 |
<p>Preparation of 5-bromo-2,2-difluoro-benzo[1,3]dioxole compounds (I) comprises reacting 2,2-difluoro-benzo[1,3]dioxole compounds (II) with bromine in the presence of at least two Friedel-Crafts catalysts, one of the catalyst being hydrogen fluoride. Preparation of 5-bromo-2,2-difluoro-benzo[1,3]dioxole compounds of formula (I) comprises reacting 2,2-difluoro-benzo[1,3]dioxole compounds of formula (II) with bromine in the presence of at least two Friedel-Crafts catalysts, one of the catalyst being hydrogen fluoride. R 1>1-4C alkyl, Br, Cl or F; and n : 0-1. [Image].</p> |
