Synthesis of 1,2,3,9a-tetrahydro-9H-imidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]indole-2-thione and 1,5,6,10b-Tetrahydroimidazo[2,1-<Emphasis Type="Italic">a</Emphasis>]-isoquinoline-2(3H)-thione derivatives

Thionation of 1,2,3,9a-tetrahydro-9H-imidazo1,2-a]indol-2-one derivative with Lawessons reagent in boiling toluene afforded 1,2,3,9a-tetrahydro-9H-imidazo1,2-a]indole-2-thione derivative. Alkylation of the latter with ethyl iodide in DMF in the presence of a strong base gave 2-ethylthio-9,9,9a-trimethyl-9,9a-dihydro-3H-imidazo1,2-a]indole. 1,5,6,10b-Tetrahydroimidazo2,1-a]isoquinoline-2(3H)-thiones were synthesized by thionation of the corresponding carbonyl substrates.Published in Khimiya Geterotsiklicheskikh Soedinenii, No 11, pp. 1695–1700, November, 2004.