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Recent studies showed that 1,4-dihydropyridine-3,5-dicarbamoyl derivatives with lipophilic groups have significant antitubercular activity. In this study, we have synthesized new derivatives of 1,4-dihydropyridines bearing carbmethoxy and carbethoxy group at C-3 and C-5 of the 1,4-dihydropyridine ring. In addition, 1H-pyrazole ring is substituted at C-4 position. These analogues were synthesized by multi-component Hantzsch reaction. The in vitro antitubercular activity of compounds against Mycobacterium tuberculosis H(37) Rv was evaluated. The lowest minimum inhibitory concentration value, 0.02 μg/mL and SI > 500, was found for dimethyl 1,4-dihydro-4-(3-(4-nitrophenyl)-1-phenyl-1H-pyrazol-4-yl)-2,6-dimethylpyridine-3,5-dicarboxylate 3f, diethyl 1,4-dihydro-4-(3-(4-fluorophenyl)-1-phenyl-1H-pyrazol-4-yl)-2,6-dimethylpyridine-3,5-dicarboxylate 4c and diethyl 1,4-dihydro-4-(3-(4-bromophenyl)-1-phenyl-1H-pyrazol-4-yl)-2,6-dimethyl pyridine-3,5-dicarboxylate 4e, making them more potent than first-line antitubercular drug isoniazid. In addition, these compounds exhibited relatively low cytotoxicity.

A series of phenothiazine clubbed pyrazolo[3,4-d]pyrimidines have been synthesized by using the Biginelli multi-component cyclocondensation reaction and their ability to inhibit growth of Mycobacterium tuberculosis in vitro have been determined. The results show that compounds 4b, 4d, and 4f exhibited excellent anti-tubercular activity with percentage inhibition of 93, 91, and 96, respectively, at a minimum inhibitory concentration (MIC) of\6.25 lg/ml, whereas compounds 4a, 4c, 4e, 4g, and 4h exhibited moderate to good anti-tubercular activity with percentage inhibition of 75, 68, 74, 54, and 63, respectively at a MIC of [6.25 lg/ml.

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The present article describes a facile one-pot synthesis of a series of eight pyrazolo[3,4-d]pyrimidines 4a-h which were evaluated for their in-vitro antibacterial activity against Mycobacterium tuberculosis H37Rv using the Alamar-Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC) in mg/mL. The compounds 4b, 4c, 4d, and 4g exhibited the best results (1.2 microg/mL) when compared with first-line drugs such as isoniazid (INH) and rifampicin (RIP). Therefore, this class of compounds could be a good starting point to develop new lead compounds in the treatment of multidrug-resistant tuberculosis.

Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.

In the present investigation ethyl 2-(4-carboxyphenylazo)acetoacetate 1 on condensation with various aromatic aldehydes in ethanolic NaOH solution yielded the corresponding chalcones 2a-j. These chalcones were further reacted with urea in the presence of base in ethanol, which led to the formation of pyrimidine derivatives 3a-j. The newly synthesized heterocyles were characterized on the basis of their chemical properties and spectroscopic data. All newly synthesized compounds were evaluated for their antimycobacterial activities against Mycobacterium tuberculosis H 37 Rv.

The synthesis of thiazolo[5,4-d]pyrimidines can be achieved from different 5- thiazolidinones, 2-butyl-1H-imidazole-5-carbaldehyde and thiourea using microwave irradiation within 5 min. The structures of the products were supported by FTIR, PMR and mass spectral data. The in vitro antimicrobial activity of the synthesized thiazolo[5,4-d]pyrimidines 1a-j, having substituents at the 1- and 3-positions, were determined by the cup-plate method against several standard strains chosen to define the spectrum and potency of the new compounds. The antimicrobial activities of the thiazolo[5,4-d]pyrimidines 1a-j are compared with those of known chosen standard drugs, viz. ampicillin, chloramphenicol, ciprofloxacin, norfloxacin and griseofulvin. .