NOPR Collection:

Newer potential quinazolinones as hypotensive agents

2013-10-13T16:41:01Z

Title: Newer potential quinazolinones as hypotensive agents Authors: Kumar, Ashok; Tyagi, Mirdula; Srivastava, V K Abstract: A series of 3-(substitutedarylidene)hydrazinoacetylamino-2-methyl-6-bromo-quinazolin-4(3H)-ones 4a-e has been prepared by the condensation of 3-(hydrazinoacetylamino)-2-methyl-6- bromoquinazolin-4(3H)-one 3 with different aromatic aldehydes. Compounds 4a-e on treatment with chloro-acetylchloride in the presence of triethylamine are converted into 3-[2'-(substitutedaryl)-3'-chloro-4'-oxo-1'-azetidinyl] aminochloroacetylamino-2-methyl-6-bromoquinazolin-4(3H)-ones 5a-e, which undergo Mannich reaction to yield compounds 6a-c. The structures of all the new compounds have been confirmed by elemental analysis and spectral studies (IR,¹H NMR and mass spectroscopy). Compounds 4a-4e, 5a-5e and 6a-6e have been evaluated for hypotensive activity and were round to exhibit activity ranging from 10-90 mmHg. The most active compound of this series is 3-[2'-(p-N-N-dimethylaminobenzylidine))-3׳-chloro-4'-oxo-]'-azetidinyl-aminoacetylamino [-2-[(p-methoxyphenyl)aminoethyl ]-2-methyl-6-bromoquinazo-lin-4(3H)-one 6d which has shown blood pressure lowering activity of 90 mmHg, which lasted for 120 min. at a dose of 2.5 mg/kg i.v. Page(s): 2142-2145

Synthetic approaches towards 3-pyridinecarbonitrile derivatives and their antimicrobial properties

2013-10-10T16:42:52Z

Title: Synthetic approaches towards 3-pyridinecarbonitrile derivatives and their antimicrobial properties Authors: Kamel, Mona M; Hussein, Manal M M Abstract: A variety of 2-alkoxy-4,6-diaryl-3-pyridinecarbonitriles 2 have been prepared via either the reaction of 1,3-diaryl-2-propen-1-ones 1 with malononitrile or the reaction of ylidenemalononitriles 6 with the proper aryl methyl ketone 7 in the appropriate alcohol in the presence of sodium. On the other hand, conducting the reaction in refluxing ethanol in the presence of ammonium acetate affords, the corresponding 2-amino-3-pyridinecarbonitriles 8. The antimicrobial properties against Gram-positive, Gram-negative, acid-fast bacteria and yeast have been screened. The prepared propenones 1a-d show considerable activity against the tested yeast as well as most of the Gram-positive and Gram-negative bacteria. A few derivatives of the prepared pyridines 2c,f,h ; 8b exhibit mild antimicrobial activity. Page(s): 2136-2141

Synthesis, characterization and antimicrobial activity of 4-phenyl-3-thiopyrimido[4,5b] quinolines

2013-10-11T16:43:51Z

Title: Synthesis, characterization and antimicrobial activity of 4-phenyl-3-thiopyrimido[4,5b] quinolines Authors: Suresh, T; Kumar, R Nandha; Magesh, S; Mohan, P S Abstract: An easy one-step synthesis of substituted pyrimido[4,5-b]quinolines 3a-e has been achieved from 2-chloro-3-formyl quinolines 1 and N-Phenyl thiourea 2. All the synthesized compounds have been biologically screened for their antibacterial and antifungal activities. Page(s): 2133-2135

Kinetics and mechanism of the oxidation of methionine by benzyltrimethylammonium tribromide

2013-10-12T16:44:07Z

Title: Kinetics and mechanism of the oxidation of methionine by benzyltrimethylammonium tribromide Authors: Goyal, Archana; Kothari, Seema Abstract: The oxidation of methionine (MTN) hy henzyltrimethylammonium tribromide (BTMAB), in 1:1 aqueous acetic acid, leads to the formation of the corresponding sulphoxide. The reaction is first order with respect to each the methionine and BTMAB. The oxidation of MTN in an atmosphere of nitrogen, failed to induce the polymerization of acrylonitrile. An addition of benzyltrimethylammonium chloride has no effect on the rate of oxidation. The rates of oxidation were determined at different temperatures and the activation parameters were calculated. The reaction rate increases with an increase in the polarity of the medium. Tribromide ion is postulated as the reactive oxidizing species. Suitable mechanism for the reaction is postulated. Page(s): 2129-2132