Vk. Ahluwalia et al., A NOVEL ONE-POT SYNTHESIS OF SUBSTITUTED 5-BENZOYL-1H,6H-PYRANO[2,3-C]PYRAZOLONE AND 5-ACETYLAMINO-1H, 6H-PYRANO[2,3-C]PYRAZOLONE, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 32(9), 1993, pp. 960-962
A convenient one-pot synthesis of some 5-benzoyl- and 5-acetylamino-1H
, 6H-pyrano[2, 3-c]pyrazolones (4) by the reaction of 2-pyrazolin-5-on
es (1) with hippuric/aceturic acid and triethyl orthoformate in the pr
esence of acetic anhydride, in good yield (75-85%) has been described.