Mohamed I. Hegab

Synthesis and antiviral evaluation of some new pyrazole and fused pyrazolopyrimidine derivatives

Some novel substituted pyrazole and pyrazolo[3,4-d]pyrimidine derivatives 2, 4, 8, and 9 were synthesized. Also, some acyclic S-nucleosides of pyrazolo[3,4-d]pyrimidine derivatives 10-13 were prepared via reaction of pyrazolo[3,4-d]pyrimidine-4(3H)-thione derivative 9 with some acyclic sugars. Moreover, the N-nucleoside derivative 14 was prepared via reaction of compound 8 with glucosamine hydrochloride. The antiviral evaluation of some selected new products showed that they have promising antiviral activity against hepatitis-A virus (HAV) and herpes simplex virus type-1 (HSV-1).

Synthesis and anti-HSV-1 evaluation of some pyrazoles and fused pyrazolopyrimidines

5-Amino-1-substituted-1H-pyrazole-4-carbonitrile derivative 1 was used as a precursor for preparation of some novel substituted pyrazole and pyrazolo[3,4-d]pyrimidine derivatives 2-10. Furthermore, the preparation of sugar hydrazone derivatives 11a,b, 12a,b and their annelated C-nucleosides 13a,b was described. Some of the prepared products revealed promising antiviral activity against herpes simplex virus type-1 (HSV-1) in comparison to Acyclovir as a control.

Synthesis, Reactions, and Antimicrobial Activity of Some Fused Thieno[2,3-d]pyrimidine Derivatives

Some new indeno[1′,2′ :4,5]thieno[2,3-d]pyrimidines were prepared from the reaction of 2-aminoindeno[2,1-b]thiophene-3-carbonitrile ( 1 ) with different reagents. Also, some indeno[1′,2′ :4,5]thieno[3,2-e]tetrazolo[1,5-c]pyrimidines and indeno[1′,2′ :4,5]thieno[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines and their isomeric [1,2,4]triazolo[1,5-c]pyrimidines were prepared. The antimicrobial evaluation of some prepared products showed that many of them revealed promising antimicrobial activity.

Synthesis And Antimicrobial Activity Of Some Cyclic And Acyclic Nucleosides Of Thieno[2,3-d]Pyrimidines

The reaction of compounds 1, 2, 3, 4, or 13 with 2-chloroethyl methyl ether or 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide, afforded some acyclic and cyclic nucleosides of thieno[2,3-d]pyrimidine derivatives. Furthermore, cyclic C-nucleosides 24 and 25 were prepared from the reaction of 20, 21 or from 26, 27 with D-glucose. The antimicrobial evaluation of some prepared products showed promising antimicrobial activity.

One-pot synthesis of N -nucleosides via 1,3-dipolar cycloaddition of 1-aza-2-azoniaallene salts to 2,3,4,6-tetra- O -acetyl-β-D-glucopyranosyl isothiocyanate\

The C=S double bond of 2,3,4,6-tetra- O -acetyl- g -D-glucopyranosyl isothiocyanate reacts with 1-aza-2-azoniaallene salts under [3+2] cycloaddition to afford (glucosylimino)-1,3,4-thiadiazoles.

Synthesis and Antitumor Evaluation of Some Newly Synthesized Pyrazolopyrimidine and Pyrazolotriazolopyrimidine Derivatives

A series of novel pyrazolo[3,4-d]pyrimidine 2b, 3, 5b, pyrazolotetrazolopyrimidine 4, and pyrazolotriazolopyrimidine derivatives 6a,b–10a,b have been synthesized and characterized by elemental analysis and spectroscopic data. Furthermore, the cytotoxicity and in vivo antitumor evaluation of some prepared compounds have been assessed, and derivatives 1a and 6b revealed promising activity in comparison to that of Cisplatin. 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.

Synthesis and pharmacological activities of some condensed 4-chloro-2,2-dialkyl chromene-3-carbaldehyde derivatives

Synthesis and pharmacological activities of some condensed 4-chloro-2,2-dialkyl chromene-3-carbaldehyde derivatives Some new hydrazono 5a,b, thiosemicarbazono 6a-c, and oximo chromenes 7a-c were prepared via the reaction of the corresponding β-chlorocarbaldehyde 3 with hydrazine, aromatic hydrazine, thiosemicarbazide and hydroxylamine hydrochloride, respectively. In addition, ether derivatives 8a-h were prepared from the corresponding aldoximes 7a-c. The new products were tested for anti-inflammatory and ulcerogenic score activities compared to indomethacin. Sinteza i farmakološko djelovanje derivata kondenziranih 4-klor-2,2-dialkil kromen-3-karbaldehida Novi hidrazono- 5a,b, tiosemikarbazono- 6a-c i oksimo kromeni 7a-c sintetizirani su iz odgovarajućeg β-klorkarbaldehida 3 i hidrazina, aromatskog hidrazina, tiosemikarbazida ili hidroksilamin hidroklorida, dok su eterski derivati 8a-h pripremljeni iz pripadajućih aldoksima 7a-c. Novi spojevi ispitani su na protuupalno i ulcerogeno djelovanje, a njihovo djelovanje uspoređeno je s djelovanjem indometacina.

Synthesis of 5-Chloro-10,11-Dihydro-5 H -Dibenzo[ a , d ]Cycloheptene-5,10-Sulfide and -5,11-Dichloro-10,11-Dihydro-5 H -Dibenzo[ A , D ]Cycloheptene-5,10-Sulfide and their Oxidation

The chlorination of 5-thioxo-10,11-dihydro-5 H -dibenzo[ a,d ]cycloheptene 2a gave 5-chloro-10,11-dihydro-5 H -dibenzo[ a,d ]cycloheptene-5,10-sulfide 4 . Chlorination of 5-thioxo-5 H -dibenzo[ a,d ]cycloheptene 2b gave the two isomers cis - and trans -5,11-dichloro-10,11-dihydro-5 H -dibenzo[ a,d ]cycloheptene-5,10-sulfide 7a,b . The two sulfides 4 and 7a,b were oxidized by using mCPBA or H 2 O 2 /AcOH to give the corresponding sulfoxides 5 and 8a,b , respectively. Treatment of the sulfide 7a,b with KI gave the primary ketone 1b together with trans -5-chloro-11-hydroxy-10,11-dihydro-5 H -dibenzo[ a,d ]cycloheptene-5,10-sulfide 9 . The structures of the new compounds were established by different spectroscopic techniques as well as single crystal X-ray diffraction for compounds 4 and 9 .

Further Studies and Synthesis of Five-membered Rings via 1,3-Dipolar Cycloaddition of 1-Aza-2-azoniaallene Cations to Isothiocyanates and Nitriles

Cycloaddition of 1-aza-2-azoniaallene salts ( 2 , 9 and 17 ) with isothiocyanates gave different types of 1,2,4-triazolium salts ( 5 , 6 and 25-34 ), and 1,3,4-thiadiazolium salts ( 12 , 14 and 19 ). The obtained products depend on: a) the ability of a substituent of the heteroallene salts to undergo a [1,2] shift as a cationic charged migrant or to act as a cationic leaving groups (as a stable carbenium ion), b) Dimroth rearrangement of the initially formed thiadiazolium salts to triazolium salts. Accordingly, 1-aza-2-azoniaallenes ( 22 and 29 ) reacted with nitriles and dinitriles to give 1,2,4-triazolium salts ( 25 , 27 and 32-34 ).

Regioselective synthesis and pharmacological activities of spirodibenzo[a, d]cycloheptene-5,2′-[1,3,4]thiadiazole derivatives

Some new 3′,5′-substituted-5H,3′ H-spirodibenzo[a, d]cycloheptene-5,2′-[1,3,4]thiadiazole and 10,11-dihydro-5H,3′ H-spirodibenzo[a, d]cycloheptene-5,2′-[1,3,4]thiadiazole derivatives 3a–n were regioselectively synthesized under 1,3-dipolar cycloaddition of 5-thiooxo-5H-dibenzo[a, d]cyclo-heptene and 5-thiooxo-10,11-dihydro-5H-dibenzo[a, d]cycloheptene with a variety of nitrilimines (generated in situ via dehydrohalogenation of the corresponding hydrazonoyl chlorides in the presence of triethylamine). The new products were tested for antiinflammatory, analgesic, and ulcerogenic score activities comparable to Indomethacin. Compounds 3i–l showed significant activity compared to Indomethacin.