2-Methoxybenzaldehyde → HCID 56612712, compound

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Reaction Steps

1,2,3,4-tetrahydro-11-oxo-11H-pyrido[2,1-b]quinazoline-8-carboxylic acid, methyl ester (2.5 g) was reacted with 2-methoxy-benzaldehyde (2.6 g) in tert.butanol (75 ml) in the presence of potassium tert.butylate (4.3 g) under stirring at reflux temperature for 8 hours. After cooling the solution was concentrated in vacuo to a small volume and the precipitate was filtered and washed with little methanol and then dissolved in water containing NaHCO3 : the solution was acidified with 23% HCl to pH=4 and the precipitate was filtered and washed with water until neutral. Crystallization from acetone gave 1.1 g of 4-(2-methoxy-benzylidene)-1,2,3,4-tetrahydro-11-oxo-11H-pyrido[2,1-b]quinazoline-8-carboxylic acid, m.p. 300° C. (dec.), N.M.R. (CDCl3 -CF3COOD) δp.p.m.: 1.93 (m) (2H,C-2 protons), 2.84 (m) (4H, C-1 and C-3 protons), 3.81 (s) (3H, --OCH3), 6.80-7.50 (m) (4H, phenyl protons), 7.70 (bs) (1H, =CH--), 8.17 (d) (1H, C-6 proton), 8.69 (dd) (1H, C-7 proton), 9.73 (d) (1H,C-9 proton).

Provenance & Evidence