13C-NMR spectra and hardness of some carbohydrate containing polyamides

Several carbohydrates containing polyamides were prepared through polycondensation at low temperature of a solution of 2,3,4,5 - tetra- O-acetylgalactaroyl dichloride with various aromatic and aliphatic diamines. The structures of the acetylated and de-O-acetylated carbohydrate polyamides were confirmed by IR and 13C-NMR spectroscopy. The thermal stability and hardness of the polymers were also investigated. The acetylated polyamides showed higher hardness than the de-O-acetylated ones, which is probably due to stiffness of the polymer chains produced by the acetyl group

Novel 4- [pyrazol-1-yl] -, 1,2,4-triazolo [4,3-c] -, triazolo [1,5-c] and tetrazolo [1,5-c] quinazolines: synthesis for potential biological activities

Several 4-pyrazolylquinazolines, 1,2,4-triazolo [4,3-c] quinazolines, and 1,2,4-triazolo [1,5-c] quinazolines of potential biological activities were prepared by cyclization of 4-hydrazino-2-methylquinazoline and 4-hydrazino-2-phenylquinazoline with mono- and 1,3-dicarbonyl compounds. The 5-phenyl-1,2,4-triazolo [4,3-c] quinazolines were also obtained by an alternative route involving cyclization of 4-chloro-2-phenylquinazoline with aroylhydrazines. The tetrazolo [1,5-c] quinazolines were synthesized by cyclization of the amidrazones with nitrous acid or by cyclization of 4-chloro-2-phenylquinazoline with sodium azide

Novel pyrazolone derivatives: synthesis and evaluation for analgesic activating

The synthesis of 3-amino-4-arylazo-2H-pyrazolin-5-one [III] was achieved by direct diazo-coupling of 3-aminopyrazolones or by hydrazinolysis of ethyl cyanoglyoxalate hydrazones. Acetylation of III gave the acetyl derivative IV or the pyrazol [3, 4-e] triazine V, depending on the reaction time. Benzoylation of III gave only the monobenzoyl derivative VI, whereas chloroaetylation gave the imidazol [1, 2-b] pyrazole VII. Representative examples of the products were tested for analgesic activity

Synthesis of pyrazolo [3,4-b] pyridine derivatives

The reaction of 3-amino-5-pyrazolones with 1, 3-dicarbonyl compounds has been shown to give either pyrazolo[l,5-a] pyrimidine or pyrazolo [3,4-b] pyridines depending on the conditions employed. The pyrazolo [3,4-b] pyridines were reported to be valuable from both the pharmacological and antimicrobial view points. Consequently, the present work comprised the investigation of the reaction of l-phenyl-3-amino-5-pyrazolone [I] with ethyl acetylpyruvate [II] aiming to synthesise pyrazolo [3,4-b] pyridine derivatives of biological interest