64076-98-8Relevant academic research and scientific papers
Nitrogen bridgehead compounds. Part 92.* Synthesis of 4-oxo-4H-pyrido[1,2-a]pyriniidine-3-carboxamides, -3-acetamides and their tetrahydro derivatives
Hermecz, Istvan,Vasvari-Debreczy, Lelle,Horvath, Agnes,Sipos, Judit,Balogh, Maria,Podanyi, Benjamin,Kovacs, Katalin
, p. 515 - 528 (2007/10/03)
N-Substituted 4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamides (6-45), -3-acetamides (59-61) and 1,6-dimethyl-4-oxo-1,6,7,8-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-carhoxamides (63-73) were synthesized in the reaction of amines and mixed anhydrides, prepared from 4-oxo-4H-pyrido[1,2-a]-pyrimidine-3-carboxylic acids (4), -3-acetic acids (58) and 1,6-dimethyl-4-oxo-1,6,7,8-tetrahydropyrido-[1,2-a]pyrimidine-3-carhoxylic acid (62) with methyl or ethyl chloroformate in the presence of triethylamine. Whereas the reaction of 6-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-acetic acid (53) with 2-phenylethylamines in boilings xylene gave the appropriate N-substituted 3-acetamides (54) and (55), reaction of 6-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-acetic acid (56) with 2-phenylethylamine afforded a pyrrolidin-5-one derivative (57). 3-Acetic hydrazides (47, 48) and (50) were prepared from ethyl 4-oxo-4H-pyrido[1,2-a]pyrimidine-3-acetates (46) and the 6,7,8,9-tetrahydro derivative (49) with hydrazine hydrate. Both 4-oxo-4H-pyrido[1,2-a]pyrimidine-3-acetic hydrazide (47) and 6,7,8,9-tetrahydro-3-acetic hydrazide (50) were converted to 6,7,8,9-tetrahydro-3-acetamides (51, 52) by refluxing them in ethanol over Raney Ni.
Condensed pyrimidines
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, (2008/06/13)
New compounds of the following formula are disclosed: 1,6-dimethyl-3-carbamoyl-4-oxo-1,6,7,8-tetrahydro-4H-pyrido(1,2-a)-pyrimidine; 1,6-dimethyl-3-(N-tertiary-butyl-carbamoyl)-4-oxo-1,6,7,8-tetrahydro-4H-pyrido(1,2-a)pyrimidine; 1,6-dimethyl-3-(N-2-phenethyl-carbamoyl)-4-oxo-1,6,7,8-tetrahydro-4H-pyrido(1,2-a)pyrimidine; 1,6-dimethyl-3-[N-(3,3-diphenyl-propyl)-carbamoyl]-4-oxo-1,6,7,8-tetrahydro-4H-pyrido(1,2-a)pyrimidine; 1,6-dimethyl-3-(N-phenyl-carbamoyl)-4-oxo-1,6,7,8-tetrahydro-4H-pyrido(1,2-a)pyrimidine; and 1,6-dimethyl-3-(N-methyl-carbamoyl)-4-oxo-1,6,7,8-tetrahydro-4H-pyrido(1,2-a)pyrimidine, as well as pharmaceutical compositions containing these compounds and a method of inhibiting thrombocyte aggregation in mammals employing a pharmaceutically effective amount of at least one of these compounds.
