Abdou O. Abdelhamid

REACTIONS WITH HYDRAZIDOYL HALIDES II [1]: SYNTHESIS AND REACTIONS OF 2-BROMOTHIENYLGLYOXAL-2-PHENYLHYDRAZONE

Abstract 2-Bromoacetylthiophene reacted with dimethylsulfide in ethanol to afford dimethylsulfonium bromide 2, which reacted with N-nitrosoacetanilide to give 2-bromo-thienylglyoxal-2-phenylhydrazone (3). 3 reacted with pyridine and with triphenylphosphine to give 4a and 4b, respectively. 3 reacted also with morpholine, sodium thiophenolate or potassium cyanide to afford the corresponding hydrazones 5a–c, respectively. 3 reacted also with potassium thiocyanate and with potassium selenocyanate to give the thiadiazoline 6a and selenadiazoline 6b. 3 is utilized also for the synthesis of several heterocycles via its reactions with malononitrile, benzoylacetonitrile, dibenzoylmethane, ω-benzenesulfonylacetophenone, N-arylmaleimides and benzalaniline. Structural assignments have been made on the basis of elemental analyses, spectral data and independent synthesis wherever possible.

Synthesis and cytotoxicity evaluation of some novel thiazoles, thiadiazoles, and pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(1H)-ones incorporating triazole moiety.

Reactions of hydrazonoyl halides and each of methyl 2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazine-1-carbodithioate and 2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazine-1-carbothioamide afforded 2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazono)-3-phenyl-5-substituted-2,3-dihydro-1,3,4-thiadiazoles and 5-(4-substituted)diazenyl)-2-(2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazinyl)-4-arylthiazoles, respectively. Analogously, the reactions of hydrazonoyl halides with 7-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-5-phenyl-2-thioxo-2,3-dihydropyrido[2,3-d]pyrimidin-4(1H)-one gave 3-(4-substituted)-8-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-6-phenyl-1-arylpyrido[2,3-d]-[1,2,4]-triazolo-[4,3-a]pyrimidin-5(1H)-ones in a good yield. The structures of the newly synthesized were elucidated via elemental analysis, spectral data and alternative synthesis routes whenever possible. Twelve of the newly synthesized compounds have been evaluated for their antitumor activity against human breast carcinoma (MCF-7) and human hepatocellular carcinoma (HepG2) cell lines. Their structure activity relationships (SAR) were also studied. The 1,3,4-thiadiazole derivative 9b (IC50 = 2.94 µM) has promising antitumor activity against the human hepatocellular carcinoma cell line and the thiazole derivative 12a has promising inhibitory activity against both the human hepatocellular carcinoma cell line and the breast carcinoma cell line (IC50 = 1.19, and 3.4 µM, respectively).

Synthesis and Antimicrobial Activity of Some New 5-Arylazothiazole, Pyrazolo[1,5-a] Pyrimidine, [1,2,4]Triazolo[4,3-a]Pyrimidine, and Pyrimido[1,2-a]Benzimidazole Derivatives Containing the Thiazole Moiety

1-(2-(4,5-Dihydro-3-(4-methyl-2-phenylthiazol-5-yl)-5-phenylpyrazol-1-yl)-4-substituted thiazol-5-yl)-2-phenyldiazene were synthesized from hydrazonoyl halides and 3-(4-methyl-2-phenyl-1,3-thiazol-5-yl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide in ethanolic triethylamine. Also, pyrazolo[5,1-a]pyrimidines, 2,3,6-trisubstituted pyridines, and pyrazolo[3,4-d]pyridazines were obtained from sodium salt of 3-hydroxy-1-(4-methyl-2-phenylthiazol-5-yl)prop-2-en-1-one and different heterocyclic amines. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible. The newly synthesized compounds were tested towards different microorganisms. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Reactions with Hydrazonoyl Halides XXX: Synthesis of Some 2,3-Dihydro-1,3,4-Thiadiazoles and Unsymmetrical Azines Containing Benzothiazole Moiety

Abstract C-Benzothiazoloyl-N-arylhydrazonoyl bromides 1a,b have been caused to react with each of methyl 2-thiazolylcyanomethinecarbodithioate (2), alkyl carbodithioates 8–10, and methyl thiocarbamates 14a-c in the presence of triethylamine to give 2,3-dihydro-1,3,4-thiadiazoles in good yields. In contrast, hydrazonoyl bromides react with each of phenylthiourea (19a), phenylthiosemicarbazide (19b), and benzoylthiosemicarbazide (19c) afforded 5-arylazothiazole 22–24(a-c) derivatives, respectively. Structures of the new compounds were elucidated on the basis of elemental analyses, spectral data, and alternative methods of synthesis whenever possible.

Reactions of Hydrazonoyl Halides 33 1 : Synthesis of Some New 2,3-Dihydro-1,3,4-thiadiazoles Containing Pyrazol-3-yl, Indolin-2-one-2-yl and Indan-1,3-dione-2-yl Moieties

Some new 2,3-dihydro-1,3,4-thiadiazoles containing pyrazol-3-yl, indolin-2-one-2-yl and indan-1,3-dione-2-yl moieties in a good yields obtained from the reaction of hydrazonoyl halides with thiocarbamate and carbodithioate in ethanolic triethylamine respectively. In contrast, pyrazolylthiourea reacts with hydrazonoyl halides under the same condition afford corresponding hydrazonoyl sulfide derivatives.

One Pot Single Step Synthesis and Biological Evaluation of Some Novel Bis(1,3,4-thiadiazole) Derivatives as Potential Cytotoxic Agents

A novel series of bis(1,3,4-thiadiazole) derivatives were synthesized in one step methodology with good yields by condensation reaction between bis-hydrazonoyl chloride 1 and various reagents. The structures of the prepared compounds were confirmed by spectral data (IR, NMR, and MS), and elemental analysis. The anticancer activity against human breast carcinoma (MCF-7) cancer cell lines was evaluated in MTT assay. The results revealed that the bis-thiadiazole derivatives 5c,d, 7b,c and 9c had higher antitumor activity than the standard drug Imatinib.

Utility of 3-Acetyl-6-bromo-2H-chromen-2-one for the Synthesis of New Heterocycles as Potential Antiproliferative Agents

Coumarin derivatives containing pyrazolo[1,5-a]pyrimidine, tetrazolo[1,5-a]pyrimidine, imidazo[1,2-a]pyrimidine, pyrazolo[3,4-d]pyrimidine, 1,3,4-thiadiazoles and thiazoles were synthesized from 6-bromo-3-(3-(dimethylamino)acryloyl)-2H-chromen-2-one, methyl 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene)hydrazine carbodithioate, 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene)hydrazine carbothioamide and each of heterocyclic amine, hydrazonoyl chlorides and hydroximoyl chlorides. The structures of the newly synthesized compounds were elucidated on the basis of elemental analysis, spectral data, and alternative synthetic routes whenever possible. Moreover, selected newly synthesized products were evaluated for their antitumor activity against a liver carcinoma cancer cell line (HEPG2-1). The results revealed that pyrazolo[1,5-a]pyrimidine 7c, thiazole 23g and 1,3,4-thiadiazole 18a (IC50 = 2.70 ± 0.28, 3.50 ± 0.23 and 4.90 ± 0.69 µM, respectively) have promising antitumor activity against liver carcinoma (HEPG2-1) while most of the tested compounds showed moderate activity.

Reactions With Hydrazonoyl Halides 45: Synthesis of Some New Triazolino[4,3‐a]pyrimidines, Pyrazolo[3,4‐d]pyridazines, Isoxazolo[3,4‐d]pyridazines, and Thieno[2,3‐b]pyridines

Abstract Triazolino[4,3‐a]pyrimidines pyrazolo[3,4‐d]pyridazines and isoxazolo[3,4‐d]pyridazines were synthesized from hydrazonoyl halides. Also, 3‐aminothieno[2,3‐b]pyridines and pyrimidino[4′,5′:4,5]thieno[2,3‐b]pyridines were synthesized from cynothioacetamide. Structures of the newly synthesized compounds were established on the basis of elemental analyses and spectral data.

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 .

Reactions with Hydrazonoyl Halides 40: Synthesis of Some New 1,3,4‐Thiadiazoles, Pyrrolo[3,4‐c]pyrazoles, Pyrazoles, and Pyrazolo[3,4‐d]pyridazines

Abstract Pyrazoles, pyrazolo[3,4‐d]pyridazines, pyrrolo[3,4‐d]pyrazole‐4,6‐diones, and 2,3‐dihydro‐1,3,4‐thiadiazoles were synthesized via reactions of hydrazonoyl bromide with each of (2E)‐3‐(dimethylamino)prop‐2‐enoyl]benzo[f]2H‐chromen‐3‐one, N‐arylmaleimides, and alkyl carbodithioates.