Sodium Hydroxide → 5-oxo-1H,5H-pyrazolo[1,5-a]quinazoline-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-hydrazinylbenzoic acid hydrochloride (1.05 g, 5.57 mmol), (E)-ethyl 2-cyano-3-ethoxyacrylate (0.9 g, 5.32 mmol) and sodium acetate (0.457 g, 5.57 mmol) in DMF (7 mL) was heated to 140° C. for 2 h then cooled. Water (5 mL) was added and the mixture was stirred at rt for 1 h then filtered. The solid was washed with H2O, EtOH and Et2O then dried. The solid was dissolved in EtOH (10 mL), treated with a 1M solution of sodium hydroxide (23 mL, 23 mmol) and the mixture was heated at 80° C. for 18 hr. The mixture was filtered hot then cooled and acidified with acetic acid and 10% HCl. The precipitated product was filtered, washed with H2O and Et2O, dried well and used without any further purification.

Provenance & Evidence