Dimethylformamide → HCID 86737689, compound

Participants

Reaction Steps

From 4,9-dihydro-6,7-dimethoxy-9-oxo-pyrazolo[5,1-b]-quinazoline-2-carboxylic acid (1.5 g; 5.2 mmole), anhydrous potassium carbonate (3.0 g; 22 mmole), methyl iodide (15 ml) and DMF (50 ml), following the procedure of Example 11, there is obtained 4,9-dihydro-6,7-dimethoxy-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic acid, methyl ester (1.8 g); mp 301°-303° (d). The crude methyl ester (1.8 g) is hydrolyzed with 1(N) sodium hydroxide solution (50 ml) as in Example 11 to give 4,9-dihydro-6,7-dimethoxy-4-methyl-9-oxo-pyrazolo-[5,1-b]quinazoline-2-carboxylic acid (0.95 g) mp 284°-5° (d), after crystallization from DMF/methanol.

Provenance & Evidence