Facile One‐Pot Synthesis and Antimycobacterial Evaluation of Pyrazolo[3,4‐d]pyrimidines

Abstract

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.

Synthesis and Biological Evaluation of Some Novel 1,4‐Dihydropyridines as Potential AntiTubercular Agents

“…In addition, pyrazoles exhibited significant antitubercular activity (11). Recognizing these facts and in continuation of our work on antitubercular agents (12–16), it appeared of interest to design and synthesize new derivatives of 1,4‐dihydropyridines bearing carbmethoxy and carbethoxy group at C‐3 and C‐5 of the DHP ring, respectively. It seems that such replacements could effectively overcome the resistant isolates, which have been attributed to a deficiency of amidase or esterase.…”

Crystal structure of N,N-dimethyl-N′-(2-methyl-4-oxo-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-3(4H)-yl)formimidamide, C14H18N4OS

“…agents is limited due to the rapidly developing drug resistance in conjunction with the unsatisfactory status of present treatments of bacterial and fungal infections [3,4]. Pyrimidine nucleus has gained potential importance in medicinal chemistry, as some of its derivatives exhibited a wide range of biological activities, such as antiviral [5][6][7][8], anticoccidials [9,10], antimicrobial [11][12][13][14], antitumor [15][16][17][18], herbicidal, antileukemic [19,20], pesticides [21], CNS agents [22], tuberculostatic [23][24][25], antileishmanial [26][27][28], radioprotectant [29], anti-in ammatory [30], and cardiovascular activities [31,32]. The biological signicance of the above heterocycle prompted us to explore the synthesis of novel pyrimidines from 3-amino-2-methyl-5,6, 7,8-tetrahydrobenzo [4,5] The asymmetric unit of the title compound contains one independent molecule.…”

Synthesis and antimycobacterial evaluation of various 6-substituted pyrazolo[3,4-d]pyrimidine derivatives

“…Also, in 13 C NMR spectra, methine proton was observed between 39.5-41.9 δ ppm. Compounds 4a-f on S-methylation with dimethyl sulphate in the presence of K 2 CO 3 afforded 4,5-dihydro-4-(aryl)-3-methyl-6-(methylthio)-1-phenyl-1H-pyrazolo [3,4-d] pyrimidines (5a-f), which was confirmed by presence of S-methyl protons as a singlet in the range of 2.01-2.16 δ ppm in 1 H NMR spectra of 5a-f. S-methyl protons were observed at 12.3-14.3 δ ppm In 13 C NMR spectra.…”

“…13 C-NMR (75 and 125 MHz) spectra were registered on a Bruker AC 200, DPX 300 and ARX 500, at 25°C, in CDCl 3 . Elemental analysis of the newly synthesised compounds was carried out on Carlo Erba 1108 analyser and are found within the range of theoretical value.…”