Microwave-assisted synthesis of double-headed derivatives of (4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-ethan-1-ol and study of their biological activity

Research on Chemical Intermediates - The present investigation involves rapid and efficient synthesis of a series of some novel derivatives for...     

A New Approach for Synthesis of 2-Thioxocytosine-5-carbonitrile as Antimicrobial Agents

Russian Journal of General Chemistry - A highly efficient synthetic methodology for the preparation of 2-thioxocytosine was achieved by the nucleophilic addition of thiourea to...     

Facile synthesis of some condensed 1,3-thiazines and thiazoles under conventional conditions: antitumor activity

1,3-Thiazine 3 was obtained from cinnamoyl thiourea derivative 2 as the kinetic control product. Refluxing of 2 with sodium ethoxide afforded pyrimidine derivative 4. Moreover, stirring of 2 with bromine/acetic acid gave thiazole 5 that was condensed with o-phenylene diamine forming benzimidazole 6. Heating of arylthiourea 8 with maleic anhydride or phenacyl chloride afforded thiazole derivatives 9 and 10, respectively. Condensation of compound 10 with o-phenylene diamine gave benzimidazole 11. Reaction of p-amino benzoic acid with chloro acetyl isothiocyanate, acetylacetone and ethylacetoacetate produced imidazole 14, enaminone 15 and crotonate 16 derivatives, respectively. Stirring a mixture of benzoyl isothiocyanate with 15 and/or 16 resulted in pyridine-2-thione 17. The yields of the prepared compounds were 41–93%. The experimental section is simple and easy. The detailed synthesis, spectroscopic data, IC₅₀ and antitumor activity of the synthesized compounds were reported. The cytotoxicity of the newly synthesized products showed that compound 4 is the most active compound towards the cancer cell line at which its reactivity is higher than that of the standard doxorubicin (anticancer reference drug).     

Synthesis of Pyrano[2,3-d]pyrimidine-2,4-diones and Pyridino[2,3-d]pyrimidine-2,4,6,8-tetraones: Evaluation Antitumor Activity

A series of some novel pyrano[2,3-d]pyrimidine 4 – 10 with 75–95% yields and pyridino[2,3-d]pyrimidine derivatives 11 – 16 with 75–92% yields is reported. The building structures have been achieved by reaction of 5-arylidene barbituric acid 2 and active nucleophile carbon or nitrogen as examples barbituric acid and acetyl acetone or refluxing of bispyrimidine-2,4,6-trione derivative 3 with cyclizing reagents such as phosphorous pentoxide, hydrazine hydrate and aminothiazole. The newly synthesized structures have been elucidated on the basis of their spectral analysis. Some selected members were screened for antitumor activity. Among the screened compounds 9 , 16 , 7 , 10 and 8 exhibited high antitumor activity.     

Practical and reliable synthesis of dialkyl N-arylphosphoramidates with nitroarenes as substrates

A new single-step transformation of readily available nitroarenes with trialkyl phosphites, which can be performed both under thermal and microwave conditions, delivers dialkyl N-arylphosphoramidates in good yields and short reaction times.     

The Synthesis of Triazolothiadiazines and Thiadiazoles From 1,2-Bis-(4-amino-5-mercapto-1,2,4-triazol-3-yl)- Ethanol and Ethane

The reaction of DL-malic and succinic acids with thiocarbohydrazide afforded 1,2-bis[4-amino-5-mercapto-1,2,4-triazol-3-yl]-ethane derivatives 3a and 3b. The reaction of 3a,b with phenacyl bromide and benzoin afforded 1,2-bis-1,2,4-triazolo [3,4-b][1,3,4]thiadiazine derivatives 4 and 5. The carboethoxymethylation of 3a and 3b gave 6a and 6b, respectively, and their reactions with carbon disulfide and benzoylisothiocyanate gave the 1,2-bis-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole 7 and 9, and with p-nitrobenzaldehyde gave a Schiff's base and dihydrothiadiazole 8. The structures were confirmed by using ¹ H and ¹³ C NMR spectra. Selected members of these compounds were screened for antimicrobial activity.     

Improvements of properties of asphalt by poly(methyl methacrylate) additives

This article presents the effect of adding poly(methyl methacrylate) (PMMA) with different molecular weights on the mechanical properties of asphalt in terms of durability, strength, and resistance to rutting. By controlling the time of reaction we obtained PMMA of two different molecular weights: PMMA1 and PMMA2. The ageing properties of polymer modified asphalts were studied using the thin film over (oven) a test. A hot storage stability test was carried out for polymer modified binder. The physical properties of asphalt modified with PMMA including penetration value and softening point were examined at two different temperatures. Resilient modulus test was evaluated by a Universal Testing Machine. Results showed that an incorporation of PMMA into asphalt binder has significantly improved its properties under studies. Indirect tensile strength test and durability performance of the modified asphalts was evaluated as well. The resulted modification was found to be dependent on the polymer molecular weight. The PMMA1 exhibited effective and cheerful results.