TETRAHYDROFOLATE COENZYME MODELS - SYNTHESIS OF TETRAHYDROIMIDAZOISOQUINOLINES AND TETRAHYDROIMIDAZOQUINOLINES

The new dihydroimidazoles 3-methyl-1,5,6,10b-tetrahydroimidazo[5,1-a] isoquinoline and 1-methyl-3,3a,4,5- tetrahydroimidazo[1,5-a]quinoline are efficiently and conveniently prepared from isoquinoline and quinoline, via 1-aminomethyl-1,2,3,4-tetrahydroisoquinoline and 2-aminomethyl-1,2,3,4- tetrahydroquinoline, respectively. Deprotonation of the fused dihydroimidazoles at the methyl substituent leads to homologation via C-alkylation, C-acylation, or C-phosphonylation-condensation. The properties of the tetrahydroimidazo[5,1- a]isoquinolines and tetrahydroimidazo[1,5-a]quinolines towards reducing agents mirror those of monocyclic dihydroimidazoles, affording aminomethyl- isoquinolines and -quinolines, respectively.