Hyam A. Abdelhadi

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.

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.

REACTIVITY OF 1-METHYLISOQUINOLINE. ONE POT SYNTHESIS OF BENZO[a]-QUINOLIZINE DERIVATIVES

ABSTRACT 1-Methylisoquinoline 1 reacts with arylidine malononitrile 2 in the presence of piperidine to give the corresponding Michael adducts pyridinoisoquinolines 5. The structures of the products 5 were established on the basis of elemental and spectral analyses and studies of their chemical behaviours.

Reactivity of 1-Methylisoquinoline. Synthesis of 2-(1-Isoquinolinemethylidene)-1,3,4-Thiadiazole Derivatives

1-methyl-3,4-dihydro-6,7-dimethoxyisoquinoline reacts with arylisothiocyanates to give the corresponding thioanilides 2 . Treatment of the latter compounds 2 with hydrazonoyl halides 3 and 10 leads to the formation of thiadiazoles 7 and 12 .

Synthesis of Tetra- and Pentaheterocyclic Compounds Incorporated Isoquinoline Moiety

7-Amino-2,3-dimethoxy-9-phenyl-5,6,9,6a-tetrahydropyridino[2,1-a]-isoquinoline-8,10-dicarbonitrile 5 was prepared via Michael addition reaction of benzylidenemalononitrile 2 with isoquinoline-1-carbonitrile 1. Reaction of 5 with triethyl orthoformate and formamide led to the formation of the corresponding 4-ethoxymethylene and 4-aminopyrimidine derivatives of benzo[a]quinolizines 6 and 7, respectively. Compound 6 reacted with hydrazine to give imino-amino compound 8. The latter compound reacted with formic acid, triethyl orthoformate, acetic anhydride or benzoyl chloride to give the triazolopyrimidine derivatives 9, 10 and 11, respectively. Compound 8 reacted with hydrazonoyl halides 12, 13 and diethyl oxalate to give triazinopyrimidine and triazolopyrimidine derivatives 16, 17 and 20, respectively.

Michael Reactions of Arylidenesulfonylacetonitriles. A New Route to Polyfunctional Benzo[a]quinolizines

Arylidenesulfonylacetonitriles react in acetonitrile with 1-methylisoquinoline and isoquinolin-1-yl-acetonitrile in the presence of piperidine to give benzo[a]quinolizines 6,9 and 7,10, respectively. The structures of the products were established on the basis of elemental and spectral analyses and their chemical reactivity.

SITE SELECTIVITY AND REGIOCHEMISTRY OF NITRILIMINES. CYCLOADDITIONS TO 1,3-DIPHENYL-2-THIONO-4-IMIDAZOLIDINONE AND ITS 5-PHENYLMETHYLENE DERIVATIVES

Abstract Nitrilimines 2 cycloadd to the C==S double bond of 1,3-diphenyl-2-thiono-4-imidazolidinone 3 to give the corresponding spiro compounds 5; while their reaction with 1,3-diphenyl-5-phenylmethylene-2-thiono-4-imidazolidinone 4 lead to the formation of the spiro compounds 6 via cycloaddition to the exocyclic C==C double bond.

Synthesis of unsymmetrical aryl-ethynylated benzenes via regiocontrolled Sonogashira reaction of 1,3,5-tribromobenzene

O acoplamento de Sonogashira do trimetilsililacetileno com 4-alcoxi-1-iodobenzenos resultou em 2-(4-(alquiloxi)fenil)etiniltrimetilsilanos, que sofrem desprotecao pela retirada do grupo TMS usando fluoreto de tetrabutilamonio (TBAF) em THF a temperatura ambiente, resultando nos 2-(4-(alquiloxi)fenil)acetilenos terminais correspondentes. O acoplamento cruzado de Sonogashira do 1,3,5-tribromobenzeno com os arilacetilenos terminais em meio aquoso resultou na formacao de derivados de benzeno mono-, di- e tri-alquinilados com rendimentos de moderados a bons. Os fatores que afetam a regiosseletividade da alquinilacao tambem foram examinados.

REACTION OF HYDRAZONOYL HALIDES WITH 2,4-DIOXOTETRAHYDROTHIAZOLE-5-THIOCARBOXANILIDES

Abstract Reaction of 3-phenyl-2,4-dioxotetrahydrothiazole-5-thiocarboxanilides 3 with hydrazonoyl halides 4 in N,N-dimethylformamide in the presence of potassium hydroxide yielded the thiadiazoline derivatives 7 and 13. The mechanism of formation of the latter products is discussed.