Synthesis and cardiotonic activity of a series of substituted 4-alkyl-2(1H)-quinazolinones.

The synthesis, cardiac fraction III cyclic nucleotide phosphodiesterase (PDE-III) inhibition, and positive inotropic activity of a series of 2(1H)-quinazolinones are reported. A general synthesis of the series involved the cyclization of 2-aminoacetophenones with potassium cyanate in acetic acid. Modifications at the 4-position of the quinazoline nucleus were best achieved by formation of the intermediate N1-acyl-N3-phenylurea from the substituted phenyl isocyanate and appropriate carboxamide.

Chemistry and hypoglycemic activity of benzimidoylpyrazoles.

A series of benzimidoylpyrazoles was synthesized and evaluated as hypoglycemic agents. Methyl 1-(N-cyclohexylbenzimidoyl)-5-methyl-3-pyrazolecarboxylate (13) and methyl 1-[N-(4-methoxyphenyl)benzimidoyl]-5-methyl-3-pyrazolecarboxylate (33) are two of the more interesting compounds. A comparison of these benzimidoylpyrazoles with classical standards (tolazamide, phenformin, and buformin) in several experimental models show that these compounds seem to combine in one molecule some of the biological activities of the beta-cytotrophic sulfonylureas and some of the activities of the biguanides.

Antihypertensive pyrrolo[1,2-c]quinazolines and pyrrolo[1,2-c]quinazolinones.

The synthesis of a variety of pyrrolo[1,2-c]quinazolines and pyrrolo[1,2-c]quinazolinones is described. Several of these compounds have exhibited antihypertensive properties in the spontaneously hypertensive rat (SHR). Structure-activity comparisons have indicated that optimal activity is obtained in both the 2-carbethoxydihydroquinazoline series (C) and 2-carbethoxyquinazolinone series (D) when there is either a carbethoxy or cyanoethyl group at position 6 and no substitution in the benzene ring, while optimal activity is obtained in the 2-methyl-quinazolinone series (D) when both position 6 and the benzene ring are unsubstituted.