5-Methyl-1,3-diphenylpyrazolo[4,3-d]oxazin-7-one

Mohammadine El Haddad and Mohamed Akssira

Laboratoire de Chimie Bioorganique & Analytique, Université Hassan II-Mohammedia, FST, BP 146, 20 650, Mohammedia, Maroc. Fax : +212 23 31 53 53 E-mail: [email protected]

Received: 18 June 2001 / Accepted: 15 December 2001 / Published: 20 December 2001

In a similar manner to the reported procedure [1,2], b-pyrazolic amino acid [3] (2 mmoles) was dissolved in acetic anhydride. The mixture was heated at 80°C with stirring. The reaction was complete after 2 hours. After cooling, the solvent was evaporated. The oily residue was dissolved in ether and kept at O°C. A white solid precipitate formed, which was collected by filtration and washed several times with ether. Yield: 85%.

Melting point = 152-153 °C.

MS: m/z = 304 (M+1).

IR (KBr, cm^-1): 1758 (C=O), 1614 (C=N), 1580 (C=N).

¹H NMR (250 MHz, CDCl₃): 2.53 (s, 3H, -CH₃), 7.39-7.56 (m, 6H, Ar-H), 8.01 (d, 2H, Ar-H, J = 8.45Hz), 8.34 (d, 2H, Ar-H, J = 8.1 Hz).

¹³C NMR (62.5 MHz, CDCl₃): 21.64 (CH₃) ; 97.63 (C_3a) ; 122.73 (2C) ; 127.9 ; 128.21(2C) ; 128.57(2C) ; 129.17(2C) ; 129.68 ; 130.62 ; 137.77 ; 150.02(C_7a) ; 151.5(C₃) ; 155.44(C₅) ; 166.53(C₇).

References

1. El Haddad, M.; Akssira, M. Molecules 2001, 6, M271.

2. Webber, S. E.; Bleckman, T. M.; Attard, J.; Deal, J. G.; Kathardekar, V.; Welsh, K. M.; Webber, S.; Janson, C. A.; Matthews, D. A.; Smith, W. W.; Freer, S. T.; Jordan, S. R.; Bacquet, R. J.; Howland, E. F.; Booth, C. L. J.; Ward, R. W.; Hermann, S. M.; White, J.; Morse, C. A.; Hilliard, J. A.; Barlett, C. A. J. Med. Chem. 1993, 36, 733.

3. El Mahdi, O.; Lavergne, J. P.; Viallefont, P.; Akssira, M. Bull. Soc. Chim. Belg. 1995, 104, 31.

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