K. R. Raghavendra

Synthesis of lignan conjugates via cyclopropanation: Antimicrobial and antioxidant studies.

Ethyl 2-(4-methoxyphenyl)-3-(thiophene-2-carbonyl)cyclopropanecarboxylates 2(a-f) and ethyl 4-aryl-7-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-5-carboxylates 4(a-f) were synthesized by simple procedure. The synthesized new compounds were screened in vitro for their antimicrobial and antioxidant activities. The compounds 2b and 4f showed excellent antibacterial activity; while 2b and 4f showed remarkable antifungal properties. The results of antioxidant activity studies revealed that compounds 4b and 4f manifested profound antioxidant potential. The docking studies were done for the final compounds. The ADME result indicates that all these molecules possess pharmaceutical properties in the range of 95% of drugs.

4-(Thio-phen-2-yl)-2-[4-(tri-fluoro-meth-yl)phen-yl]-2,3-di-hydro-1,5-benzo-thia-zepine.

In the title compound, C20H14F3NS2, the seven-membered thiazepine ring adopts a slightly distorted twist–boat conformation. The mean plane of the five-membered thiophene ring fused to the thiazepine ring is twisted by 32.3 (3) and 55.6 (4)° from the benzene and phenyl rings, respectively. In the crystal, inversion dimers linked by pairs of weak C—H⋯N interactions are observed.

An Accessible Route for the Synthesis of Novel Lignan Derivatives and Their Biological Evaluation

2-(Aryl(thiophen-2-yl)methyl)succinic acids (4a – 4d), 3-(aryl(thiophen-2-yl)methyl)dihydrofuran-2,5-diones (5a – 5d), 7-aryl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carboxylic acids (6a – 6d), and ethyl 7-aryl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carboxylates (7a – 7d) were synthesized via Stobbe condensation of aryl(thiophen-2-yl)methanones and diethyl succinate. The newly synthesized compounds (5a – 5d, 6a – 6d, and 7a - 7d) were screened in vitro for their antimicrobial and antioxidant properties. Compounds 5b, 6d, and 7d exhibited promising antifungal and antibacterial activity against various microorganisms tested. Compounds 7d and 7b showed remarkable DPPH radical scavenging abilities.

2-(3,4-Di-meth-oxy-phen-yl)-4-(thio-phen-2-yl)-2,3-di-hydro-1,5-benzo-thia-zepine.

In the title compound, C21H19NO2S2, the seven-membered thiazepine ring adopts a slightly distorted twist boat conformation. The dihedral angle between the benzene rings is 67.4 (2)°. The mean plane of the thiophene ring is twisted by 59.3 (2) and 87.7 (2)° from the mean planes of the benezene rings. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds generate R 2 2(20) loops.

Crystal structure of (E)-N-phenyl-N′-[1-(thio­phen-2-yl)ethyl­idene]formo­hydrazide

In the title compound, C13H12N2OS, the planes of the thiophene and phenyl rings are nearly perpendicular to each other, making a dihedral angle of 86.42 (12)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming a helical chain along the b-axis direction.