1,3-Di:sila cyclobutane(s) for silicon carbide prods. - mfd. by pyrolysing alkoxy tri:sila alkane(s) at 400-800 deg. C. at atmos. pressure or vacuum, avoiding alkali metal, for high yield and purity

摘要

1,3-disilacyclobutanes are of formula (I); and R1-R4 = Me, OMe, OEt or Ph. Prodn. comprises pyrolysis of alkoxy-trisila-alkane derivs. of formula (II) (with R5 as for other R gps.) at 400-800 deg. C at atmos. pressure or under vacuum. Pref. (I) have R1 = R4 = Me and R2 = R3 = OMe, or R1-R3 = OMe and R4 = Me, or R1-R4 = OMe, or R1 = OMe, R2 = R3 = Cl and R4 = Me, or R1 = R4 = OMe and R2 = R3 = Cl, or R1 = R4 = OEt and R2 = R3 = Cl. Pref. (II) are obtd., e.g. by reacting chloromethylsilanes of formula R1R2R3SiCH2Cl with Si in the presence of Cu catalysts, as described in Korean Pat. Appl. No. 91-1055, and reacting with R4MgCl and/or with an alcohol R5OH. USE/ADVANTAGE - Prod. mixts. can be sepd. by distn..