SYNTHESIS OF THIOPHENE DERIVATIVES BEARING A SILICON ATOM

Synthesis of thiophene derivatives containing a silicon atom is descri bed. Silylation of 2-thienylmethyl chloride (12) with trichlorovinylsi lane or chloro(chloromethyl)dimethylsilane was accomplished by additio n of 12 to a mixture of Mg and the former reagent in THF or by additio n of a mixture of 12 and the latter reagent to a mixture of Mg in THF to give dichloro(2-thienylmethyl)vinylsilane (13) or chloromethyl(dime thyl)(2-thienylmethyl) (18). The Grignard reagent (19) of 18 reacted w ith carbon dioxide, dimethyl carbonate or benzaldehyde to produce dime thyl(2-thienylmethyl)silylacetic acid (20), methyl dimethyl(2-thienylm ethyl)silylacetate (21) or -[dimethyl(2-thienylmethyl)silyl]-1'-phenyl ethanol (22).