Acid assisted reactions of 1,2-dihydro-2-(4,5-dihydroimidazol-2-yl)phthalazin-1-ol with aryl(heteroaryl) methyl ketones

摘要

A series of the 1,2-dihydro-2-(4,5-dihydro-1H-imidazol-2-yl)-1,2-dihydrophthalazin-1-yl]-2-arylethanone hydrochlorides (2a-i) was synthesized by acid assisted reaction of phthalazine pseudobase (1) with aryl(heteroaryl) methyl ketones. A similar reactions of 1 with cyclohexanone and benzo-1,4-dioxan-2-one afforded 1, 2, 3, 4, 6, 7, 15b, 15c-octahydro-4aH-imidazo[1,2-a]phthalazino[2,1-c]quinazolin-4a-ol (5) and 7-[2-(4,5-dihydro-1H-imidazol-2-yl)-1,2-dihydrophthalazin-1-yl]-1,4-benzodioxin-2(3H)-one (6), respectively. Structures of these compounds were confirmed by IR and NMR spectroscopy as well as X-Ray crystallographic analysis of the free base (3a). Biological activity of the compounds (2) was examined on rabbit aortic rings.