2-Methylbenzaldehyde → HCID 56612994, compound

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Reaction Steps

1,2,3,10-tetrahydro-10-oxo-cyclopenta[d]pyrido[1,2-a]pyrimidine-7-carboxylic acid (3.12 g) in methanol (145 ml) containing 2.9 g of sodium methoxide was reacted with 4.86 g of 2-methyl-benzaldehyde under stirring at reflux temperature for 144 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 1.9 g of 3-(2-methyl-benzylidene)-1,2,3,10-tetrahydro-10-oxo-cyclopenta[d]pyrido[1,2-a]pyrimidine-7-carboxylic acid, m.p. 300°-302° C., NMR (CF3COOD) δ ppm: 2.49 (s) (3H, --CH3), 3.36 (s) (4H, cyclopentane protons), 7.42 (m) (3H, phenyl protons), 7.64 (m) (1H, phenyl proton), 7.81 (bs) (1H, =CH--), 8.40 (d) (1H, C-5 proton), 9.11 (d d) (1H, C-6 proton), 10.23 (d) (1H, C-8 proton).

Provenance & Evidence