Acetic Anhydride → HCID 1512467, compound

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Reaction Steps

The mixture of the above obtained methyl (5-hydroxy-1-phenyl-1H-pyrazol-3-yl)acetate (Compound of Formula (IV), 1.85 g), acetic anhydride (1.00 ml) and MeC(OEt)3 (2.50 ml) was refluxed for 1 h. and left overnight at an ambient temperature. Resulting precipitate was collected by filtration and washed with ethyl ether (10 ml) in order to obtain crude product methyl[(4Z)-4-(1-ethoxyethylidene)-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl]acetate (1.20 g, 80% purity) in 50% yields. 1HNMR (400 MHz, CDCl3, ppm): 1.42 (3H, t, 7.1 Hz), 2.78 (3H, s), 3.73 (3H, s), 3.76 (2H, s), 4.31 (2H, q, 6.9 Hz), 7.16 (1H, t, 7.2 Hz), 7.37 (2H, t, 7.6 Hz), 7.97 (2H, d, 8.0 Hz). MS (ESI+): 303.3; MS (ESI−): 301.2.

Provenance & Evidence