الفهرس 
english title page
ContentsOnly 14 pages are availabe for public view
 |  | from | 184 |  |  |
| | | from | 184 | | |
Abstract
This thesis includes four chapters. The first one is an introduction which is composed of three parts. The first part covering a brief literature survey on the synthesis of pyrazole and pyrazolo[5,1-b]quinazoline derivatives. The second part is a simple introduction covering the concept of inflammation, cyclooxygenase/ lipoxygenase enzymes. The third part deals with the classification of anti-inflammatory drugs based on their mode of action as well as anti-inflammatory activity of pyrazoles and quinazoline derivatives. The second chapter involves the objectives of the work, the scientific rationale of designing the new target compounds based on molecular hybridization and structural modification of both selective COX-2 inhibitors and dual COX-2/5-LOX inhibitors. It also demonstrates schemes (1-3) for the preparation of the new derivatives.Scheme 1 implicates the synthesis of 2-cyanoacetohydrazide (I) by reacting a mixture of ethyl cyanoacetae and hydrazine hydrate. The reaction of compound I with sodium ethoxide in precence of absolute ethanol yielded key precursor 3-amino-1H-pyrazol-5(4H)-one (II) which undergoes an unexpected cyclization with anthranilic acid to afford pyrazolo[5,1-b]quinazoline-2,9(1H,4H)-dione (III). The reaction of compound III with an equimolar amount of appropriate aromatic aldehyde in acetic acid buffered with sodium acetate yielded target 3-(substituted benzylidene)pyrazolo[5,1-b]quinazoline-2,9(1H,3H)-dione derivatives IVa-j. Scheme 2 is concerned with the preparation of the target compounds 4-substitutedbenzylidene-4,5-dihydro-5-oxo-1H-pyrazol-3-ylamino)benzoic acid VIa-h by condensation of 4-(4,5-dihydro-5-oxo-1H-pyrazol-3-ylamino)benzoic acid (V) and the appropriate aromatic aldehyde