Synthesis of new 4-(4,5-diphenyl-1h-imidazol- 2-yl)tetrazolo[1,5-a]quinolines from tetrazolo[1,5-a]quinolines

Nitrogen-Rich Tetrazolo[1,5-b]pyridazine: Promising Building Block for Advanced Energetic Materials

Two metal-free explosives, tetrazolo[1,5-b]pyridazine-containing molecules [6-azido-8-nitrotetrazolo[1,5-b]pyridazine-7-amine (3at) and 8-nitrotetrazolo[1,5-b]pyridazine-6,7-diamine (6)], were obtained via straightforward two-step synthetic routes from commercially available reagents. Compound 3at displays an excellent detonation performance (D_v = 8746 m s^-1 and P = 31.5 GPa) that is superior to commercial primary explosives such as lead azide and diazodinitrophenol (DDNP). Compound 6 has superior thermal stability, remarkable insensitivity, and good detonation performance, strongly suggesting it as an acceptable secondary explosive. The initiating ability of compound 3at has been tested by detonating 500 mg of RDX with a surprisingly low minimum primary charge of 40 mg. The extraordinary initiating power surpasses conventional primary explosives, such as commercial DDNP (70 mg) and reported 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide (ICM-103) (60 mg). The outstanding detonation power of 3at contributes to its future prospects as a promising green primary explosive. In addition, the environmentally benign methodology for the synthesis of 3at effectively shortens the time from laboratory-scale research to practical applications.

Synthesis and quantitative structure-activity relationship study of substituted imidazophosphor ester based tetrazolo[1,5-b]pyridazines as antinociceptive/anti-inflammatory agents

A high-yielding general synthesis of imidazophosphor ester based tetrazolo[1,5-b]pyridazines is described. A conjugated reaction between 3,6-diazidopyridazine and different types of phosphonyl carbanion reagents followed by intramolecular cyclization afforded the target products, by using sodium ethanolate solution as a reaction medium. Among the products, five compounds, at a dose of 50 mg per kilogram body weight, showed a notable antinociceptive and anti-inflammatory activity without toxic side-effects.

Elaborating on efficient anti-proliferation agents of cancer cells and anti-inflammatory-based N-bisphosphonic acids

Methylenebisphosponic acid tetraethyl ester (1) was added to 2-azido-7a-e and 2-chloroquinoline-3-chalcones 10a-e in boiling sodium ethanolate solution to give, via Michael addition, tetrazolo[1,5-a]quinoline-8a-d, 13a and 2-chloroquinoline-based bisphosphonates 11a-d, 14a in E-configuration. Further acid hydrolysis afforded the respective BP-acid analogues E-9a-d, 12a-d, 13b, and 14b in excellent yields. Anti-tumor activity screening for the new BP-acids at a dose of 10 µM utilizing 44 different human tumor cell lines representing breast, ovary, prostate, lung, and CNS cancer as well as leukemia and melanoma was carried out. Eight of ten tested compounds exhibited remarkable anti-tumor activity against breast and prostate cancer, and a promising anti-tumor sensitivity toward ovarian cancer and melanoma. Conversely, there was only scattered activity against leukemia and no noticeable action of these BP-acids on CNS or lung cancer. Based on the prediction results (PASS program), anti-inflammatory activity of the new acids was also determined in vivo, by the acute carrageenin induced paw edema in rats. Many of these compounds showed anti-inflammatory properties at a dose of 50 mg/kg body weight.