Heterocyclizations of pregnenolone: Novel synthesis of thiosemicarbazone, thiophene, thiazole, thieno[2,3-b]pyridine derivatives and their cytotoxicity evaluations

Synthesis, anti-inflammatory and anti-ulcer evaluations of thiazole, thiophene, pyridine and pyran derivatives derived from androstenedione

“…Steroids bearing heterocycles fused to the D-ring of the steroid nucleus have been of pharmaceutical interest [12][13][14]. Recently our research group reported the heterocyclization of some steroids followed by their cytotoxic evaluation towards cancer cell lines [15][16][17]. In the present paper, we report on the efficient synthesis of androstenedione possessing thiazole, thiophene, pyridine and pyran ring systems.…”

The Knoevenagel reactions of pregnenolone with cyanomethylene reagents: Synthesis of thiophene, thieno[2,3-b]pyridine, thieno[3,2-d]isoxazole derivatives of pregnenolone and their in vitro cytotoxicity towards tumor and normal cell lines

“…Compound 127.3, 128.8, 130.2, 134.9, 146.3, 149.1, 153.2, 154.0, 163.1 Recently, our research group was involved through a series of heterocyclization of pregnenolone to form thiophene, pyrazole and pyridine derivatives as antitumor agents [24,25]. Through the earlier work, we reported the uses of pregnenlone to form hydrazide-hydrazone and thiosemicrbazone derivatives.…”

Palladium (0) catalyzed Suzuki cross-coupling reactions of 2,4-dibromothiophene: selectivity, characterization and biological applications

“…[1,2] One such important class of compounds is biaryl thiophenes, which have been successfully used as chemotherapeutic, [3] anti-inflammatory, [4] antibacterial, [5] antifungal, [6] antiviral, [7] antioxidant, [8] insecticidal, [9] anti-nociceptive, [10] anti-tubercular, [11] anti-diabetic [12] and anti-depressant agents, [13] Earlier, the regioselective couplings of dibromothiophenes have been studied in detail, [14,15] Schroter and co-workers revealed in their work that the coupling of 2,4-dibromothiophene can be successfully achieved by following the Suzuki cross-coupling reaction, whereas Kumda or Sonogashira found that the couplings preferably occurs at C-2 position in thiophenes. [2] Varello and co-workers reported the one-pot couplings of 2,4-dibromothiophene through the Suzuki-Miyaura coupling reaction.…”

“…[2] Varello and co-workers reported the one-pot couplings of 2,4-dibromothiophene through the Suzuki-Miyaura coupling reaction. [16] Proutiere and co-workers performed Suzuki cross-coupling reactions by using a catalyst based on the dinuclear Pd(I)-Pd(I) complex and {[PtBu 3 ]-PdBr} 2 . The authors found that in the case of brominated thiophenes, the cross-coupling preferably occurs at the C-2-position.…”