| 摘要 |
The invention relates to a process for the preparation of compounds of formula I <IMAGE> (I) wherein R is mono- or disubstituted lower alkyl, the substituents being selected from halogen and lower alkoxy, with the proviso that said substituents are not present at the carbon atom of the lower alkyl radical R linking the group R to the remainder of the molecule of formula I; R1 is hydrogen, lower alkyl, phenyl or phenyl-lower alkyl; and X is chloro or bromo; which comprises reacting an acetal of formula II, <IMAGE> (II) wherein R and R1 are as defined above, with at least one compound of formula R2-X, wherein R2 is hydrogen or X-SO, in which last mentioned case the reaction mixture must contain a catalytically effective amount of N,N-di-lower alkyl-lower alkanoylamide(s) and wherein X is as defined with respect to the compounds of formula I. The compounds of formula I are useful intermediates, suitably for the synthesis of pharmaceutical or fungicidal compounds.
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