Synthesis of novel thiazolopyrimidine and thiazolothiatriazine derivatives

The synthesis and characterization of several substituted thiazolopyrimidines and thiazolothiatriazines are described. 2-Amino-4-arylthiazoles were cyclized with ethyl cyanoacetate and chlorosulphonyl isocyanate to provide the target compounds. Two of the synthesized compounds were evaluated for their antiinflammatory activity. Thiazole derivatives are associated with diverse pharmacological and biological activities such as antibacterial[1-3] antifungal[4] anthilmintic[5-8], antiinflammatory[9-14], antiallegric [15] antianginal[16] and diuretic activities[17]. This work describes the synthesis and the structure elucidation of novel fused thiazolopyrimidine and thiazolothiatriazine derivatives

Conductometric determination of some pharmaceutically important thiol compounds

A simple and sensitive electro-analytical method was developed for the determination of five pharmaceutical compounds containing thiol group; namely, N-acetylcysteine, captopril, D-penicillamine, 6-mercaptopurine and thioguanine. By utilizing the reaction of the thiol group with silver ions, small amounts of the studied compounds were determined conductometrically in aqueous medium using silver nitrate as titrant. The mean percentage recoveries ranged from [100.3 +/- 0.9] to [100.84 +/- 0.74]. The proposed method was successfully applied to the determination of the studied compounds in dosage forms, and the results were in good agreement with those obtained using the official methods

Synthesis of certain 1,3,4oxadiazoles, 1,2,4-triazoles and 1,3,4-thiadiazoles as potential chemotherapeutic agents

A series of five membered heterocycles namely 5-substituted-4-acetyl-2-[2-chloro-4 nitrophenyl]- 1,3,4-oxadiazolines 6-10, 4-substituted aminomethyl-2-[2-chloro-4-nitrophenyl]-1,3,4-oxadiazoline-5-thiones 12-15, 2-substituted-5-[2-chloro-4-nitrophenyl]-1,3,4-oxadiazoles 22-27, 4-substituted-3-[2-chloro-4-nitrophenyl]-5-phenyl-1,2,4-triazoles 28-30 and 2-substituted amino-5-[2-chloro-4-nitro-phenyl]-1,3,4-thiadiazoles 36-40, were synthesized. Eight representative compounds were tested for their invitro antimicrobial activity against some pathogenic microorganisms, some of them were proved to be active

Studies on the synthesis of certain sulphur compounds as antimicrobials, antishistosoma and Molluscidies

Interaction of 3, 3-dimercapto-1-[2-thienyl]-2-propen-1-one [I] with alkylhalides, acid chloride gave the S, S-disubstituted derivatives [II, IV], condensation of [I] with aldehydes afforded different products according to the reagent used. In concentrated hydrochloric acid it gives the dithioacetals [V]; while in glacial acetic acid, the chalcone [VI] was the unexpected product. Sulphurization of [I] with P4S10 afforded 5 [2-thienyl]-1,2-dithiacyclopenten-3, thione [VII] in a satisfactory yield; while bromination of [VII], followed by boiling in water gave 5 [2-thienyl]-1, 2-dithiacyclopenten-3-one [IV]. Bromination of [IX] yielded the 4-bromoderivative [X] which on treating with methanolic potassium hydroxide hydrolyses and through interreaction, 2, 5-di [2-thienyl]-1, 4-dithiacyclohexadiene-3, 6-dicarboxylic methylester [IX] was collected. Desulphurization of [XV] followed by alkaline hydrolysis gave 2, 4-di [2-thienyl] thiophene 3, 5-dicarboxylic acid [XVIII]. Oxidative cyclization of furfurylidene thiosemicarbazone gave 2-amino-5 [2-furyl]-1, 3, 4- thiadiazole [XIX] which on treating with isocyanates; namely, naphthyl, and/or cyclohexyl gave the disubstituted ureas [XX]. Condensation of disubstituted urea derivative with bromoethylacetate or/and chloroacetyl chloride obtained the imidazolidinone derivative [XXI], while with dibromoethane yielded the hedantoin derivative [XXII], screening of most derivatives showed activities

2,4-bis [substituted] -5nitropyrimidines of expected diuretic action

Interest in pyrimidine diuretics have been intensified, since the discovery of the diuretic action of xanthines. A large series of pyrimidine derivatives was prepared, and its diuretic activity has been established. Also, several sulphonamides and disulphonamides are potent carbonic anhydrase inhibitors and effective diuretic agents. Therefore, this work describes the synthesis of new 2,4-bis [substituted]-5-nitro-pyrimidine derivatives, some of them include the sulphonamide moiety, which are expected to possess biological activity as diuretic agents

Synthesis and spectroscopic studies of Novel type of unsaturated sugars

Reaction of carboethoxy acetonylidene triphenyl phosphorane [A] with aldehydo and keto sugars [la-d] led to the formation of the corresponding carboethoxy acetonylidene derivatives [2a-d], which constitute useful synthetic intermediates. Their spectroscopic data indicated the unique E configuration between the two olefinic protons and the presence of a keto enol equilibrium, in which the enolic structure stabilized by celation. Conversion of [2a] into a new type of 3 substituted coumarin [3] was established

Alkyl malonamido ester derivatives and their analogues

The chemical reactivity of methylene group of I was examined through diazocoupling. IR spectra of the obtained products 1 a-e exclude the possibility of the presence of the diazo tautomer [from a] in equilibrium with the hydrazo tautomer [from b], which is the more stable thermodynamically. The B aminobutyrate 2 was found to exist in equilibrium 2 reversible reaction 2a. Aliphatic aldehydes adds to the NH of the B aminocrotonate tautomer 2a resulting in the corresponding 1,3 oxazine derivatives 3a and b. The alkyl malonamido sugars 4 and 5 was obtained by the direct cylation of II and III, respectively. 4 was easily converted to 3 substituted coumarin 6, while methyl malonamidoaziridine derivative 5 did not. The reactivity of the methylene groups was discussed. The IR and H-NMR data were examined in details