1,2,4-triazines and condensed derivatives—XVI

3 - Alkylthio - 6,7 - dihydro - [1.2.4]triazino - [1.6- c ]quinazolin - 5 - ium - 1 - olates ( 3 ), prepared by condensation of 3 - alkylthio -6-(2- aminophenyl) - 1,2,4 - triazin - 5(2 H ) - ones ( 1 ) with aldehydes, ketones or their equivalents are transformed by thermolysis and/or acid treatment into 3 - alkylthio - [1.2.4]triazino[5.6- b ]indoles ( 4 ) and/or 4-(5- alkylthio - s - triazol -3-yl)- quinolines ( 5 ). Alkylation and acylation reactions of the compounds 5 are discussed, as well as their NMR and UV spectra and those of their alkylation and acylation products.