Hamdi M. Hassaneen

Synthesis and Antimicrobial Activity of Some New Pyrazole, Fused Pyrazolo[3,4-d]-pyrimidine and Pyrazolo[4,3-e][1,2,4]- triazolo[1,5-c]pyrimidine Derivatives

Hydrazonyl bromides 2a,b reacted with active methylene compounds (dibenzoylmethane, acetylacetone, ethyl acetoacetate, phenacyl cyanide, acetoacetanilide, ethyl cyanoacetate, cyanoacetamide and malononitrile) to afford the corresponding 1,3,4,5-tetrasubstituted pyrazole derivatives 5-12a,b. Reaction of 12a,b with formamide, formic acid and triethyl orthoformate give the pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4-d]pyrimidin-4(3H)one and 5-ethoxymethylene-aminopyrazole-4-carbo-nitrile derivatives 13-15a,b, respectively. Compounds 15a,b reacted with benzhydrazide and hydrazine hydrate to afford pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine and [4-iminopyrazolo-[3,4-d]pyrimidin-5-yl]amine derivatives 16a,b and 17a,b. Reactions of compounds 17a,b with triethyl orthoformate and carbon disulfide give the corresponding pyrazolo[4,3-e]-[1,2,4]triazolo[1,5-c]pyrimidine derivatives 18a,b and 19a,b, respectively.

Synthesis of [1,2,4]triazolo[3,4-a]isoquinolines and pyrrolo[2,1-a]isoquinolines using α-keto hydrazonoyl halides

Abstract Treatment of α-keto hydrazonoyl halides 1 with 3,4-dihydro-6,7-dimethoxyisoquinoline 3 and its 1-methyl derivative 4 in the presence of triethylamine in tetrahydrofuran at reflux afforded the corresponding cycloadducts 6 and 9 , respectively. The same halides 1 react with 1-cyanomethyl-3,4-dihydro-6,7-dimethoxyisoquinoline 5 and afforded pyrrolo[2,1-a]isoquinoline derivatives 12 in high yield.

Synthesis and biological activity of some new pyrazoline and pyrrolo[3,4-c]pyrazole-4,6-dione derivatives: reaction of nitrilimines with some dipolarophiles.

Several 1,3-diaryl-5-(cyano-, aminocarbonyl- and ethoxycarbonyl-)-2-pyrazoline, pyrrolo[3,4-c]pyrazole-4,6-dione and 1,3,4,5-tetraaryl-2-pyrazoline derivatives were prepared by the reaction of nitrilimine with different dipolarophilic reagents. The new compounds were characterized using IR, 1H-NMR, 13C-NMR and mass spectra. Biological screening of some compounds is reported.

Reaction of carbanions of β-diketones and β-keto esters with hydrazidic bromides

Abstract The carbanions of acetylacetone, dibenzoylmethane, ethyl acetoacetate and ethyl benzoylacetate react with hydrazidic bromides ( 2 ) in ethanol at room temperature to give substituted pyrazoles ( 3–6 ) respectively in good yields. The procedure appears to be a convenient and unequivocal method for preparing a particular pyrazole isomer. The structure assignments of the compounds prepared were based on elemental analyses and spectral and chemical evidence.

Facile synthesis of thiadiazolo [2,3-b] quinazoline derivatives via the Japp-Klingemann Reaction

Abstract Diazotized anathranilic acid and its methyl ester react with substituted α-thiocyanatoacetoacetanilides 3a–c to give in both cases the corresponding thiadiazolo [2,3- b ] quinazolines 6a–c , respectively. A mechanism is proposed and it is substantiated by synthesis of 6a from N-(2-car☐yphenyl)-C-phenylcarbamoyl hydrazidoyl chloride 8a or its N-(2-methoxycarbonylcarbonylphenyl) analogue 8d .

The reaction of organic molecules on solid surfaces. 1. The facile deuteration of active methylene compounds with water-d2-treated alumina

A procedure has been developed for the preparation of deuterated alumina. Treatment of ketones, active methylene compounds, and acidic hydrocarbons with this solid resulted in the deuteration of the compounds at acidic sites. Deuterated molecular sieves are also effective in these deuterations.

Synthesis and Reactivity of 2-(6,7-Diethoxy-3,4-dihydroisoquinolin-1-yl)acetonitrile towards Hydrazonoyl Halides

The synthesis of 2-(6,7-diethoxy-3,4-dihydroisoquinolin-1-yl)acetonitrile (1) has been performed by ring closure of the corresponding amide according to the Bischler-Napieralski method (Scheme 1). Based on spectroscopic data, the tautomeric 2-(tetrahydroisoquinolin-1-ylidene)acetonitrile is the actual compound. The reactions of 1 with alpha-oxohydrazonoyl halides 4 in the presence of Et3N led to 2-(aryldiazenyl)pyrrolo[2,1-a]isoquinoline derivatives 8 (Scheme 2), whereas with C-(ethoxycarbonyl)hydrazonoyl chlorides 14, 2-(arylhydrazono)pyrrolo[2,1-a]isoquinoline-1-carbonitriles 16 were formed (Scheme 4). The structures of the products were established from their analytical and spectroscopic data and, in the case of 8b, by X-ray crystallography.

Novel synthesis of 1,2,4-triazolo[4,3-a]pyrimidin-5-one derivatives

Abstract 1,2-Dihydro-2-thioxopyrimidin-4(3H)ones 6 react with C-ethoxycarbonyl-N-arylhydrazonoyl chlorides 1 to give 1,2,4-triazolo[4,3-a]pyrimidines 11 in good yield. The latter products 11 react with benzenediazonium chloride, nitrous acid, acetyl chloride and chloroacetyl chloride to give the corresponding substitution products 16–18. The structures of the newly synthesized compounds are established on the basis of chemical and spectroscopic evidence.

Synthesis and reactions of some 2-thienyl- and 2-thenoyl-derivatives of thiazole and thiadiazoline and their selenium analogs

Abstract 2-(Thiocyanatoacetyl)thiophene 2 and its selenium analog 3 couple with diazotized anilines and yield 3-aryl-2-imino-5-(2-thenoyl)-2,3-dihydro-1,3,4-thiadiazoles 6 and 3-aryl-2-imino-5-(2-thenoyl)-2,3-dihydro-1,3,4-selenadiazoles 7 respectively. The reactions of both 6 and 7 with nitrous acid, acetic anhydride and benzoyl chloride are described. Azo coupling of 2-amino-4-(2-thienyl)thiazole 17 and its selenazole analog 18 with diazotized anilines yielded the arylazo derivatives 19 and 20 respectively. Reaction of the hydrazidoyl bromide 16 with potassium thiocyanate, potassium selenocyanate, thiourea and selenourea yields 6, 7, 19, and 20 respectively.

Aryl hydrazidates—I. Synthesis and their conversion into hydrazides : A new chapman-like rearrangement in the hydrazone series

Abstract N-arylbenzhydrazidic halides (I) with phenols and thiophenol in ethanol in presence of sodium ethoxide give aryl N-arylbenzhydrazidates (II) and phenyl thiohydrazidates (V), respectively. The esters II resisted hydrolysis but strong acid cleaved them to 2-aroyl-1-arylhydrazines (VII). At high temperatures esters of type II (but not V) undergo quantitative intramolecular rearrangement to give 2-aroyl-1,1- diarylhydrazines (XIV). Structural assignments have been made on the basis of IR and UV spectra and independent synthesis.