الفهرس 
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Abstract
Several novel 2,3-dihydroquinazolin-4(1H)-ones bearing either chalcone , pyrazole or thiazole moieties have been synthesized with a survey of their analgesic and anti-inflammatory activities In addition, novel 3,4-dihydro-1H-benzo[e][1,2,4]triazepin-5(2H)-ones have been synthesized with a survey of their C.N.S. activities.
The starting material in this investigation was anthranilic acid (I) which was utilized to obtain the key intermediates N-alkyl isatoic anhydrides (IIIa,b) via its reaction with either dimethylsulphate or ethyl iodide in aqueous sodium carbonate solution to give the alkylated product II a,b which were then cyclized under the effect of ethylchloroformate.
To obtain the target 2,3-dihydroquinazolin-4(1H)-ones, the following routes were followed:
1- Refluxing N-alkyl isatoic anhydride (IIIa,b) with p- amino acetophenone in glacial acetic acid for 4 hours afforded the intermediate N- (4-acetylphenyl) -2- (alkylamino) benzamides (IVa,b).
2- Cyclization of intermediates IVa,b was achieved using formalin in ethanol containing catalytic amount of acetic acid to form the 2,3-dihydroquinazolin-4(1H)-one derivatives Va,b.
3- Condensation of Va,b with aromatic aldehyde was conducted in methanol in the presence of sodium hydroxide to yield the desired chalcones VIa-h.
4- Cyclization of chalcones VIa-d was performed using either hydrazine hydrate or phenyl hydrazine to afford the novel 4,5-dihydro-1H-pyrazoles VIIa-d or their N-phenyl analogs VIIe-h .
5- Condensation of compound Va with thiosemicarbazide was achieved in ethanol containing catalytic amount of acetic acid to obtain the novel hydrazinecarbothioamide VIII intermediate.
6- The hydrazinecarbothioamide intermediate VIII was cyclized using phenacyl bromides in refluxing ethanol with further addition of anhydrous sodium acetate to afford the novel thiazole containing compounds IXa,b.
On the other side, the target 3,4-dihydro-1H-benzo[e][1,2,4] triazepin-5(2H)-ones were obtained adapting the following steps:
1- Reacting N-methyl isatoic anhydride (IIIa) with phenylhydrazine in ethanol containing catalytic amount of acetic acid afforded the key intermediate 2-(methylamino)-N’-phenylbenzohydrazide(X).
2- Cyclization of the playmaker intermediate X with formalin was conducted in ethanol in the presence of drops of acetic acid to give the six-membered 2,3-dihydroquinazolin-4(1H)-one XI upon refluxing while the seven-membered 3,4-dihydro-1H-benzo[e][1,2,4] triazepin-5(2H)-ones XII was formed by stirring the reactants together at room temperature.
3- Condensation of intermediate X with aromatic aldehyde in refluxing acetic acid for 6 hours gave only the novel seven membered 3,4-dihydro-1H-benzo[e][1,2,4] triazepin-5(2H)-ones XIIIa-h.
4- Moreover, the intermediate X was cyclized under the effect of carbon disulfide in potassium hydroxide ethanolic solution to afford the novel 2-thioxo- 3,4-dihydro-1H-benzo[e][1,2,4] triazepin-5(2H)-one (XIV).
5- Reacting N-methyl isatoic anhydride (IIIa) with either nicotinic or isonicotinic acid hydrazides gave the amide intermediates XV or XVI.
6- Cyclization of the former amide intermediates XV and XVI with formalin in ethanol containing catalytic amount of acetic acid afforded the six membered 2,3-dihydroquinazolin-4(1H)-one XVII and the seven membered 3,4-dihydro-1H-benzo[e][1,2,4] triazepin-5(2H)-ones XVIII respectively.