5,6,7,8-Tetrahydro-3-amino-2-methyl-l[2H~-thioxoisoquinoline-4-carboni(t2r)i lree acted with carbon
disulphide in alcoholic KOH followed by acidification with HCI to produce pyrirnidotetrahydroisquinoline
dithiole (3), which when allowed to react with halocompounds, gave the compounds (5-9).
It also reacted with acrylonitrile to produce compound (10). When compound (2) was allowed to react
with ethylorthoformate in the presence of Ac,O, the corresponding ethoxy azornethene derivative
(11) was obtained, which when allowed to react with arnines or hydrazine, in order to obtain
pyrimidoisoquinoline (U)p,ro duced mainly the starting material (2).