Verfahren zur Herstellung alkylsubstituierter Phenothiazine

摘要

1,140,089. Alkyl phenothiazines. GEIGY (U.K.) Ltd. 8 May, 1967 [6 May, 1966], No. 20014/66. Heading C2C. [Also in Division C5] The invention comprises compounds of the formula where R1 and R2 are alkyl of 1-9 carbon atoms. The compounds are prepared by reacting isobutylene with a compound of the formula where R3 and R1 are H or alkyl of 1-9 carbon atoms, in the presence of a Bronsted acid catalyst, the proportion of isobutylene being in excess of the stoichiometric equivalent of the phenothiazine compound.