Abstract
N-Acylation and N-alkylation of 5-amino-6-methyl-3-phenyl-4 (3H)-pyrimidinone (I) were carried out and the products were examined for analgesic and antiinflammatory activities. The reaction of I with α-bromopropionyl bromide or chloroacetyl chloride followed by treatment with 40% aqueous dimethylamine gave 5-(α-dimethylaminopropionamido)- or 5-(N, N-dimethylglycyl) amino-6-methyl-3-phenyl-4 (3H)-pyrimidinone (IIc or IIe). The reaction of 3, 4-dihydro-1, 6-dimethyl-5-dimethylamino-4-oxo-3-phenylpyrimidinium iodide (IV) with several alkylamines such as propylamine, isobutylamine, sec-butylamine, and allylamine in acetonitrile gave 5-alkylamino-3, 4-dihydro-1, 6-dimethyl-4-oxo-3-phenylpyrimidinium iodides (IVa-d), whose reduction with sodium borohydride in methanol gave 5-alkylamino-1, 2-dihydro-1, 6-dimethyl-3-phenyl-4 (3H)-pyrimidinones (VIIa-d). The reaction of I with benzaldehyde or p-methoxybenzaldehyde gave 5-benzylidene (or p-methoxybenzylidene) amino-6-methyl-3-phenyl-4 (3H)-pyrimidinones (VIIIa, b). Compounds I and VIIIa showed analgesic and antiinflammatory activities in mice and rats.
