64628-80-4Relevant academic research and scientific papers
Process for the preparation of 2-(2',2',2'-trihalogenoethyl)-4-halogenocyclobutan-1-ones
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, (2008/06/13)
A process for the preparation of 2-(2',2',2',-trihalogenoethyl)-4-halogenocyclobutan-1-ones of the formula STR1 in which one of the radicals R1 and R2 is methyl and the other is hydrogen or methyl, or R1 and R2 together are an alkylene group having 2 to 4 carbon atoms, and X and Y are each chlorine or bromine, comprising reacting a 2,4,4,4-tetrahalogenobutyric acid chloride in the presence of an organic base with an ethylene compound which is disubstituted in 1-position by the radicals R1 and R2, as defined above, to form a 2-(2',2',2'-trihalogenoethyl)-2-halogenocyclobutan-1-one and then rearranging the latter, in the presence of a catalyst, into a 2-(2',2',2'-trihalogenoethyl)-4-halogenocyclobutan-1-one of the above formula; said 2-(2',2',2'-trihalogenoethyl)-4-halogenocyclobutan-1-ones being valuable intermediates for the preparation of 2-(2',2'-dihalogenovinyl)-cyclopropanecarboxylic acid and its insecticidally active esters; as well as the 2-(2',2',2'-trihalogenoethyl)-4-halogenocyclobutan-1-ones of the above formula and the intermediates utilized for their preparation.
