Triethylamine → 2-[4-(4-Amino-6,7-dimethoxyquinazolin-2-yl)-1-piperazinyl]-2,4,6-cycloheptatrien-1-one

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Reaction Steps

A suspension of 2-(1-piperazinyl)-4-amino-6,7-dimethoxyquinazoline (2.48 g, prepared as described by T. H. Althuis and H.-J. Hess, J. Med. Chem., cited above), triethylamine (2.3 g) in butanol (190 ml) was stirred at room temperature for 2 hr and 2-methoxy-2,4,6-cycloheptatrien-1-one (2.06 g) was added. The mixture was refluxed for 48 hr, evaporated and chromatographed through silica gel using dichloromethane-methanol (9:1). The appropriate fractions were evaporated to give 1.73 g of the title compound. The latter material was stirred for 2 hr in a solution of hydrogen chloride in methanol and evaporated. The residue was crystallized from dichloromethane-methanol to give the title compound as the hydrochloride salt (0.835 g): mp 220°-224° C.; uv max (MeOH) 246 (ε=51740) and 343 nm (ε=25525); nmr(DMSO-d6) δ 3.55 (m, 4H), 3.85 (s, 6H), 4.05 (m, 4H), 7.0 (m, 5H), 7.75 (s, 1H) and 7.85 (s, 1H); and Anal. Calcd for C21H23N5O3.HCl: C, 58.66% H, 5.63% N, 16.29% and Found: C, 57.62% H, 5.50% N, 16.38% H2O, 1.86%.

Provenance & Evidence