Hussein A. Emam

Heteroaromatization with ketene dithioacetals: Part I. Synthesis of some novel 5-amino-1-(1,3,4-thiadiazol-2-yl) and 1-(1,3,4-thiadiazin-2-yl)pyrazole-4-carbonitriles

5-Amino-3-methylthio-1-(1,3,4-thiadiazol-2-yl) and 1-(1,3,4-thiadiazin-2-yl)pyrazole-4-carbonitriles have been prepared from 5-aminopyrazoles using ketene dithioacetals as starting materials.

Synthesis of 9-Methoxy and 9-Acetoxy-3-amino-1-(4-methoxyphenyl)- 1H-benzo[f]chromene-2-carbonitriles via 2-(Imino-piperidin-1-yl-methyl)- 3-(4-methoxyphenyl)acrylonitrile as Intermediate

Several new 1H-benzo[f]chromene derivatives (3aÐd) were prepared by the reaction of 7-substituted-2-naphthols (1a,b) with substituted α-cyano-4-methoxycinnamonitriles (2a,b) together with 2-(imino-piperidin-1-yl-methyl)-3-(4-methoxyphenyl)acrylonitrile (4) as intermediate. Also, the reaction of 1a,b with 4 without catalyst afforded 9-methoxy and 9-acetoxy- 3-amino-1-(p-methoxyphenyl)-1H-benzo[f]chromene-2-carbonitrile (3b,e). The reaction of 3a,b with different electrophilic and nucleophilic reagents afforded the 12H-7-oxa-8,10-diazabenzo[ a]anthracene derivatives 5, 9, 10 and 1H-benzo[f]chromene derivatives 6Ð8, 11.

HETEROAROMATIZATION WITH KETENE DITHIOACETALS: PART II. SYNTHESIS OF SOME NOVEL 5-AMINOPYRAZOLE-3-CARBONITRILE, 3-CARBOXAMIDE AND PYRAZOLO[3,4-d]PYRIMIDIN-4-ONE DERIVATIVES AS ANTIMICROBIAL AGENTS

Abstract Ketene dithioacetals la-d are utilized for synthesis of pyrazoledithiocarboxylates 2a-d and arylaminopyrazoles 4a,b with two different substituents (o-ethoxy and p-diethylminosulfonyl) in aryl residue. Some transformation of the dithioesters 2 ate described. After that arylaminopyraroles 4a,b are converted to pyrazolopyrimidine derivatives 8–11.

REACTIONS WITH HYDRAZONOYL HALIDES XVII[l]. SYNTHESIS AND REACTIONS OF 1-BROMO-2-[4-(N-PIPERIDINO-SULFONYL)PHENYL]ETHANEDIONE-1-ARYLHYDRAZONE

Abstract The reaction of sulfamidohydrazonoyl bromide 3 with nucleophiles led to displacement of the bromide. Treatment of 3 with potassium thiocyanate or potassium selenocyanate gave 2-imino-1,3,4-thiadiazolines 5 and 2-iminoselenadiazolines 6 respectively. Reaction of 3 with thiourea and phenylthiourea yielded the thiazole derivatives 15 and 16, while dithioesters 26(or 27) reacts with 3 to afford 2,3-dihydro-1,3,4-thiadiazoles 30–32.

Chemistry and tautomerism of coupling products of diazotised sulfamethoxazole with some compounds containing an active methylene group

Azo compounds (2–5) bearing a sulfamethoxazole moiety were prepared. The action of hydrazinecarbodithioate derivatives on (2–4) afforded pyrazoledithiocarboxylates (8–10).

REACTIONS WITH HYDRAZONOYL HALIDES XIV[1]. A CONVENIENT SYNTHESIS OF 2,3-DIHYDRO- 1,3,4-THIADIAZOLE DERIVATIVES

Abstract Hydrazonoyl halides react with methyl arylmethylenehydrazinecarbodithioate in the presence of triethylamine to give 2,3-dihydro-1,3,4-thiadiazoles.

Activated Nitriles in Heterocyclic Synthesis: Synthesis ofPyrano[2,3-d]pyrimidine andPyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidineDerivatives

Several newnaphtho[2′,1′:5,6]pyrano[2,3-d ]pyrimidineshave been synthesized via hydrazinolysis of a2-ethoxymethylideneaminonaphtho[1,2-b ]pyran;polysubstitutedpyrano[3,2-e ][1,2,4]triazolo[1,5-c ]pyrimidineshave also been prepared.

REACTIONS OF CYCLODIPHOSPH(V)AZANES WITH PHENOLIC ALDEHYDES AND HYDROXYCINNAMONITRILE DERIVATIVES

Abstract Cyclodiphosphazane derivatives incorporated formyl and acrylonitrile moieties 2a, b, 4, 5 are reported. Various (formylphenyl) N-arylphosphoramidic chloride esters 7a-e were also prepared. The postulated mechanisms for the formation of such compounds are rationalized. Its U.V., IR 1H-NMR and mass spectra were discussed.

NEW DERIVATIVES OF IMINOCYCLODIPHOSPHAZANE, CHLOROPHOSPHAZOBENZYLIDENECYANO-ETHYL KETONE AND DICINNAMOYLPHOSPHORTRIAMIDE

Abstract [(Arylidenecyanoacetyl)imino]cyclodiphosphazanes 3,4-chloroanilinodichlorophosphazo (4-nitmbenzylidene) cyanomethyl ketone 5, [(4-substituted benzylidenecyanoacetamido) (4-substituted anilino)] chlorophosphazobenzylidenecyanomethyl ketone 6 and di[(p-nitro-α-cyanocinnamoyl) (p-tolyl)] phosphortriamide 7 were synthesized from the reaction between cyclodiphosphazanes 1 and arylidene-cyano-acetamides 2. The postulated mechanism for the formation of such products were rationalized. The structures assigned were supported by UV, IR, 1H NMR and mass spectra.

SULFUR CONTAINING ACTIVATED NITRILES: SYNTHESIS OF THIOPHENE, PYRIDINE-2,6-DITHIONE,3,5-DIARYLANILINE AND PYRID0[2,3-z]PYRIMIDINE DERIVATIVES

Abstract [l-(4-N.N-dimethylaminosulfonephenyl)ethylidene]malononitrile 2a was used as starting material in the synthesis of thiophene. pyridine-2,6-dithione, pyrido[2,3-d]pyrimidine, 3,5-diarylaninline, enamine and enol ether derivatives.