Reactions of 1,3-dioxoimidazo[1,5-b]isoquinolinium bromides with nucleophiles

Abstract

Treatment of 10-bromo-1,3-dioxoimidazo[1,5-b] isoquinolinium bromides 2, 1,3-dioxoimidazo[1,5-b]isoquinolinium bromides 4, and tetrahydro-1,3-dioxo-1H-imidazo[1,5-b]isoquinolinium bromides 7 with selected nucleophiles gave adducts which were respectively 5-substituted 10-bromoimidazo[1,5-b] isoquinoline-1,3(2H,5H)-diones 3,5-substituted imidazo[1,5-b] isoquinoline-1,3(2H,5H)-diones 5 and 5-substituted 10,10a-dihydroimidazo[1,5-b]isoquinoline-1,3(2H,5H)-diones 8. The adduct with cyanide (Reissert compound)5i reacted with benzyl chloride to yield 5-benzyl-1,2,3,5-tetrahydro-1,3-dioxo-2-propylimidazo[1,5-b] isoquinoline-5-carbonitrile 6. Both adducts 5i and the dihydro-Reissert compounds 8l and 8m were hydrolysed to the corresponding carboxylic acids. Reaction of isoquinolinium bromide 7a with phenylmagnesium bromide afforded 2,3,10,10a-tetra-hydro-3-hydroxy-2-methyl-3,5-diphenylimidazo[1,5-b]isoquinolin-1 (5H)-one 9.