Non-Steroidal Antiinflammatory Agents, II1): Synthesis of Novel Pyrazole and Pyrazoline Derivatives of 4(3H)-Quinazolinone Nicht-steroidale Antiphlogistika, 2. Mitt.1): Synthese neuer Pyrazol- und Pyrazolin-Derivate des 4(3H)-Chinazolinons
✍ Scribed by A. M. Farghaly; I. Chaaban; M. A. Khalil; A. A. Behkit
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 264 KB
- Volume
- 323
- Category
- Article
- ISSN
- 0365-6233
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✦ Synopsis
Antiinflammatory and/or analgesic activities have been ascribed to compounds containing the 4(3H)quinaz~linone~~~) or pyrazole moiety47). Continuation to the previous work') in the field of the synthesis of non-steroidal antiinflammatory 4(3H)quinazolinones, the present investigation deals with the synthesis of new compounds having the pyrazole or pyrazoline and 4(3H)quinazolinone moieties in one molecule, hoping that such combination might improve their antiinflammatory activity.
a,gunsaturated ketones when mated with hydrazine hydrate achieve cyc l i o n to the corresponding pyrazoline derivative^^*^). whereas, when arylhydraziis are used, pyrazole derivatives are formed"'Z'.
In the present investigation, the designed compounds were prepared according to the reaction sequences outlined in the Scheme. The key intermediates 3a-h were prepared by condensation of la-di3-") with the arylgly~xals'~~'~) 2a,b. Heating 3a-h with hydrazine hydrate in EtOH for 15 min afforded the pyrazoline derivatives 4a-h. When heating was prolonged for 12 h, the 3-amino derivative 5 was obtained. This might be due to cyclization of the side chain as well as hydrazinolysis at the 3-po~ition'**'~). The formation of the pyrazoline derivatives 4a-h was confirmed by IRand 'H-NMR-spectra as well as by the preparation of the N-acyl derivatives 6a-c. On the other hand, when 3a-h were heated with arylhydrazines in ethanol or glacial acetic acid, the pyrazole derivatives 7a-x were the products. for ax cf. Tables 14 Scheme -* BiarisonR, Wander