1-(o-Hydroxyphenyl)-3-phenylpropenone N-Benzoylhydrazone

As part of a research programme targeting novel molecules derived from o-hydroxyaryl ketone hydrazones[1,2], we synthesised 2,2´-dihydroxybenzophenone N-carbonylethoxyhydrazone.

Both starting materials, ethylcarbazate as well as 2,2´-dihydroxybenzophenone, are commercially available and they were supplied by Aldrich. Ethylcarbazate (0.49 g, 4.7 mmol) was added to a solution of 2,2´-dihydroxybenzophenone (1 g, 4.67 mmol) in propanol-1 (10 mL). The reaction mixture was refluxed for 24 hours. It was then allowed to cool at room temperature. Subsequently, it was stored in the refrigerator overnight. The precipitation which was formed was then filtered to give the desired hydrazone (1.26 g, 90 %). The product was identified by ¹H NMR, ¹³C NMR and MS and it was subjected to elemental analysis without further purification.

M.p. 177-179 °C.

¹H NMR (300 MHz, DMSO-d₆): 1.28 (t, 3H), 4.20 (q, 2H), 6.73-6.81 (m, 2H), 6.99-7.13 (m, 4H), 7.31-7.45 (m, 2H), 9.96 (s, 2H), 12.72 (s, 1H).

¹³C NMR (75 MHz, DMSO-d₆): 14.4, 61.3, 116.4, 116.9, 117.2, 118.4, 119.5 (2 carbons), 129.5 (2 carbons), 130.5, 131.2, 152.6, 153.5, 154.7, 158.2.

MS m/z (AP+): 301 [M+1]⁺, 273, 255, 212.

Anal. Calc. for C₁₆H₁₆N₂O₄: C 63.99, H 5.37, N 9.33; found: C 64.05, H 5.43, N, 9.39.