Synthesis of pyrazino (1, 2-a) indoles

Conclusion 1-Aryl-10-methylpyrazino(1,2-a)indoles are prepared by the condensation of ammonium acetate in acetic acid solution and the dibutyl acetals of 2-aroylindolyl-1-acetaldehydes which are formed by the reaction of the sodium derivatives of 2-aroyl-3-methylindoles with bromoacetaldehyde dibutyl acetal. 1-Aryl-1,2,3,4-tetrahydro-10-methylpyrazino(l,2-a)indoles are prepared by the reduction of the 1-aryl-10-methylpyrazinoindoles with sodium in alcohol. Furthermore, the synthesis of N-alkyl-dialkylamino derivatives of the 2-aroyl-3-methylindoles are carried out by the alkylation of the appropriate indoles with bisdiethylaminomethane and alkyldialkylamino chlorides.Translated from Khimiko-Farmatsevticheskii Zhurnal, No. 12, pp. 3–7, December, 1968.