M. Fekry Ismail

New convenient one-step synthesis of 4-arylphthalaz-1 -ones

Abstract 4-Arylphthalaz-1-ones ( 2a–e ) are prepared by the hitherto unknown reaction of N-aminophthalimide ( 1 ) with aromatic hydrocarbons under Friedel-Crafts conditions. The reaction of N-aminophthalimide with Grignard reagents presents another convenient method for the synthesis of 4-alkyl or 4-arylphthalaz-1-ones.

Behaviour of 2-subst1tuted 6,8-dibromo-3,1-benzoxazin-4-ones towards o-phenylenediamine and anthranilic acid ; a case of unusual cleavage of 6,8-d1bromo-2-methyl-3,1-benzoxazin-4-one

Abstract 6,8-Dibromo-2-methyl-3,l-benzoxazin-4-one (1) reacts with o-phenylenediamine to give a mixture of 3,5-dibromoanthranilic acid (2), 2-methylbenzimidazole (3) and 3-(o-aminophenyl)-6,8-dibromo-2-methylquinazolin-4-one (4). However, when the reaction was conducted in ethanol or in the absence of solvent at elevated temperature, a mixture of (2) & (3) was obtained. A similar cleavage of (1) took place when it was allowed to react with anthranilic acid yielding a mixture of (2) and N-acetylanthranilic acid (6). The reaction of o-phenylenediamine with 6,8-dibromo-2-phenyl-3,1-benzoxazin-4-one (7) proceeded normally to give 3-(o-aminophenyl)6,8-dibromo-2-phenylquinazolin-4-one (8) or 2-benzoyl-amino-3, 5-dibromo-N-(o-aminophenyl)benzamide (9), depending upon the reaction conditions.

CONVENIENT ONE-POT CONVERSION OF 2-PHENYL-3, I-BENZOXAZIN-4-ONE TO 2.(O-BENZOYLAMINOPHENYL)-1,3,4-OXADIAZOLIN-5-THIONE

Abstract 2-Phenyl-3,1-benzoxazin-4-one (1) reacted with a mixture of hydrazine hydrate and carbon disulphide in the presence of potassium hydroxide to give 2-(o-benzoylaminophenyl)-1,3,4-oxadiazolin-5-thione (2) which was also formed in better yield by the reaction of o-benzoylaminobenzhydrazide (5) with carbon disulphide and potassium hydroxide. The reaction of (2) with ethyl iodide, formaldehyde in the presence of morpholine, and with amines was also investigated.

SYNTHESIS AND SOME REACTIONS OF 4-AROYL-6-ARYL PYRIDAZIN-3(2H)-THIONES

Abstract 4-Aroyl-3-chloro-6-aryrylpyridazines[1] (1) react with thiourea to give 4aroyl-6-arylpyri-dazin-3 (2H)-thiones (2) respectively[2–7]. The compounds 2 reacted with dimethyl sulphate, hydrazine hydrate and hydroxylamine hydrochloride to give 4-aroyl-6-aryl-3-metylthiopyri-dazines 5, pyrazolinopyridazines 7 and isoxazolopyridazine 8, respectively. The compounds 2a-c reacted in alkaline ammonium hydroxide solution with sodium hypochlorite solution to give the isothiazolopyridazines 10a-c.

Reaction of N-Arylcitraconisoimidium Perchlorates with Aromatic Hydrocarbons Under Friedel-Crafts' Conditions, a New and Convenient One-Step Method for the Synthesis of β-Aroyl-α-aryl-N-arylbutyramides

Abstract A number of β-Aroyl-α-aryl-N-arylbutyramides (4a-h) have been synthesized using a new methodology involving arylation at the A,β-unsaturated ketonic systems of N-aryl-citraconisoimidium perchlorates (2a-c), followed by a subsequent ring opening via addition on the carbonyl group to give the title compounds (4a-h).