Differing reactivities and products in the reaction of some N-methylimidazol-2-yl,oxazol-2-yl- and thiazol-2-ylsilanes and -stannanes with acid chlorides

Some new N-methylimidazoles, oxazoles and thiazoles (compounds 7-15 ) with a keto-function in the 2-position have been synthesized by the reaction of heterocyclic substituted silanes and stannanes with the corresponding acid chlorides. In cases where the silylated heterocycles needed more drastic reaction conditions the use of the stannylated heterocycles was indicated. In the reaction of benzothiazol-2-yltrimethyl-stannane ( 6 ) with acetyl chloride the ester 17 and the bibenzothiazolinylidene 18 were formed. The reaction of 6 with chloromethyl methyl ether afforded the olefin 19 as the only product. Mechanisms for the above reactions are discussed.