Design and synthesis of 2-methylthio-3-substituted-5,6-dimethylthieno [2,3-d] pyrimidin-4(3H)-ones as analgesic, anti-inflammatory and antibacterial agents

Design, synthesis, and spasmolytic activity of thiophene-based derivatives via Suzuki cross-coupling reaction of 5-bromothiophene-2-carboxylic acid: their structural and computational studies

In the current research work, a facile synthesis of a series of novel thiophene-based derivatives of 5-bromothiophene-2-carboxylic acid ( 1 ) have been synthesized. All analogs ( 5a - 5e , 10a - 10f ) were obtained from the coupling reaction of 5-bromothiophene-2-carboxylic acid ( 1 ) and different arylboronic acids with moderate-to-good yields under controlled and optimal conditions. The structures of the newly synthesized compounds were characterized through spectral analysis and their spasmolytic activity, and most of the compounds exhibited potentially good spasmolytic effect. Among the synthesized analogs, compound phenethyl 5-(3,4-dichlorophenyl)thiophene-2-carboxylate ( 10d ) particular showed an excellent spasmolytic effect with an EC ₅₀ value of 1.26. All of the compounds were also studied for their structural and electronic properties by density functional theory (DFT) calculations. Through detailed insight into frontier molecular orbitals of the compounds and their different reactivity descriptors, it was found that the compounds 10c and 5c are the most reactive, while 10a is the most stable in the series. Furthermore, compounds 10c and 5c showed a very good NLO response with the highest β values.

Palladium(0) catalyzed Suzuki cross-coupling reaction of 2,5-dibromo-3-methylthiophene: selectivity, characterization, DFT studies and their biological evaluations

Thiophene derivatives have shown versatile pharmacological activities. The Suzuki reaction proved a convenient method for C-C bond formations in organic molecules. In the present research work novel derivatives of 2,5-dibromo-3-methylthiophene (3a-k and 3l-p) has been synthesized, via Suzuki coupling reaction in low to moderate yields. A wide range of functional groups were well tolerated in reaction. Density functional theory investigations on all synthesized derivatives (3a-3p) were performed in order to explore the structural properties. The pharmaceutical potential of synthesized compounds was investigated through various bioassays (antioxidant, antibacterial, antiurease activities). The compounds 3l, 3g, 3j, showed excellent antioxidant activity (86.0, 82.0, 81.3%), respectively by scavenging DPPH. Synthesized compounds showed promising antibacterial activity against tested strains. 3b, 3k, 3a, 3d and 3j showed potential antiurease activity with 67.7, 64.2, 58.8, 54.7 and 52.1% inhibition at 50 µg/ml. Results indicated that synthesized molecules could be a potential source of pharmaceutical agents.

Copper-mediated N-Arylation of Methyl 2-Aminothiophene-3-carboxylate with Organoboron Reagents

A practical protocol for the synthesis of N-arylated methyl 2-aminothiophene-3-carboxylate has been developed via Chan-Lam cross-coupling. The desired products were synthesized by cross-coupling of methyl 2-aminothiophene-3-carboxylate with both arylboronic acids and potassium aryltrifluoroborate salts in moderate to good yields. A broad range of functional groups was well tolerated.

Regioselective synthesis of 2-(bromomethyl)-5-aryl-thiophene derivatives via palladium (0) catalyzed suzuki cross-coupling reactions: as antithrombotic and haemolytically active molecules

Background

It is seen that the regioselective functionalizations of halogenated heterocycles play an important role in the synthesis of several types of organic compounds. In this domain, the Suzuki-Miyaura reaction has emerged as a convenient way to build carbon-carbon bonds in synthesizing organic compounds. Some of the most important applications of these reactions can be seen in the synthesis of natural products, and in designing targeted pharmaceutical compounds. Herein, we present the regioselective synthesis of the novel series of 2-(bromomethyl)-5-aryl-thiophenes 3a-i,via Suzuki cross-coupling reactions of various aryl boronic acids with 2-bromo-5-(bromomethyl)thiophene (2).

Results

The synthesized compounds were screened for their haemolytic and antithrombolytic activities. The novel compounds 3f, 3i showed highest 69.7, 33.6% haemolysis of blood cells, respectively. The antithrombolytic activity of the compounds was found to be within low to moderate against human blood clot. The compound 3i showed potent clot lysis (31.5%).

Conclusions

Considering these results, it is concluded that the synthesized compounds can be used as a promising source of therapeutic agents.

Iodine catalysed synthesis and antibacterial evaluation of thieno-[2,3-d]pyrimidine derivatives

A new route via iodine catalysed heterocyclisation of 2-amino-4,5-dimethylthiophene-3-carboxamide with aromatic aldehydes affording a series of thieno[2,3- d]pyrimidine derivatives in a single step have been developed. Some of these compounds exhibited antibacterial activities comparable to Streptomycin as reference drug.