Benzaldehyde → HCID 54009854, compound

Participants

Reaction Steps

1,2,3,10-tetrahydro-10-oxo-cyclopenta[d]pyrido[1,2-a]pyrimidine-7-carboxylic acid methyl ester, m.p. 153°-154° C. (5 g) in methanol (300 ml) containing 6.45 g of sodium methoxide was reacted with 10.9 g of benzaldehyde under stirring at reflux temperature for 96 hours. After cooling and concentration in vacuo to a small volume the precipitate was filtered and treated with acetic acid and then with water; the crude compound was recovered by filtration, washed with water until neutral and crystallized from CH2Cl2 /methanol and then from dioxane to give 3.25 g of 3-benzylidene-1,2,3,10-tetrahydro-10-oxo-cyclopenta[d]pyrido[1,2-a]pyrimidine-7-carboxylic acid, m.p. 309°-310° C., NMR (CF3COOD) δ ppm: 3.44 (m) (4H, cyclopentane protons), 7.68 (m) (6H, =CH-- and phenyl protons), 8.44 (d) (1H, C-5 proton), 9.15 (d.d) (1H, C-6 proton), 10.23 (d) (1H, C-8 proton).

Provenance & Evidence