NISCAIR Online Periodicals Repository Collection: IJC-B Vol.44B(03) [March 2005]

Novel bridgehead nitrogen bisheterocyclic systems: Synthesis, stereochemistry and antimicrobial activity of p-bis[2H, 5H-4-oxo-thiazol-3-yl]phenylenes and p-bis[cis-5H-3,3a-dihydropyrazolo[3,4-d]thiazol-6-yl]phenylenes

Title: Novel bridgehead nitrogen bisheterocyclic systems: Synthesis, stereochemistry and antimicrobial activity of p-bis[2H, 5H-4-oxo-thiazol-3-yl]phenylenes and p-bis[cis-5H-3,3a-dihydropyrazolo[3,4-d]thiazol-6-yl]phenylenes

Authors: Mohan, Jag; Kumar, Ashok

Abstract: The facile synthesis of p-bis[cis-3,3a-dihydro-5H-pyrazolo[3,4-d]thiazol-6-yl]phenylenes 4 has been achieved by the condensation of p-bis[4-substituted phenylimine]phenylenes 1 with thioglycollic acid in toluene, using Dean-Stark water separator, to give p-bis[2H,5H-4-oxo-2-(p-substituted phenyl)thiazol-3-yl]phenylene 2, which on condensation with arylaldehydes furnishes 5-arylidene derivatives 3 followed by treatment with 2,4-dinitrophenylhydrazine. The antibacterial and antifungal activities of some of the compounds have also been evaluated.

Page(s): 631-634

Novel synthesis and ring closure reactions of 3-hydrazino-1,2,4-triazolo[3,4-b]benzothiazole

Title: Novel synthesis and ring closure reactions of 3-hydrazino-1,2,4-triazolo[3,4-b]benzothiazole

Authors: Kapratwar, S B; Baheti, K G; Kuberkar, S V

Abstract: 3-Hydrazino-1,2,4-triazolo[3,4-b]benzothiazole 2 is prepared by heating 3-chloro-1,2,4-triazino[3,4-b]benzothiazole-4(H)-one 1 with hydrazine hydrate. This transformation takes place with decarbonylation resulting in ring contraction and simultaneous replacement of chlorine by hydrazino group. Compound 2 on heating independently with urea and carbon disulphide in the presence of alkali gave 3'-hydroxy 3 and 3'-mercapto-1,2,4-triazolo[4',5':1,5]-1,2,4-triazolo[3,4-b] benzothiazole 4 respectively. Treatment of cold solution of 2 in phosphoric acid with sodium nitrite solution affords 1,2,3,4-tetrazolo[1',5':1,5]-1,2, 4-triazolo[3,4-b]benzothiazole 5. 3'-Aryl-1, 2, 4-triazolo[4',5':1,5]-1, 2, 4-triazolo[3,4-b] benzothiazoles 7a-e have been also prepared by the reaction of 2 with aryl aldehydes in the presence of acetic acid.

Page(s): 625-627

Synthesis of imidazole, coumarin and isoxazole containing new triheterocyclic compounds and their derivatives

Title: Synthesis of imidazole, coumarin and isoxazole containing new triheterocyclic compounds and their derivatives

Authors: Rajanarendar, E; Karunakar, D; Srinivas, M

Abstract: Reaction of substituted 4-amino-3-methyl-5-styrylisoxazoles 1 with 3-(2-bromoacetyl)coumarin 2 in abs. ethanol leads to the formation of 3-[2-(3-methyl-5-styryl-4-ylamino)acetyl]chromen-2-ones 3, which are subsequently cyclised by treatment with KSCN to 3-[1-(3-methyl-5-styryl-isoxazol-4-yl)-2-mercapto-1H-imidazol-4-yl]-1-benzopyran-2H-ones 4. 2-Mercaptoimidazoles 4 on treatment with ClCH₂COCl in DMF / abs. ethanol give unexpected product esters 5. The reaction of 4 with phenacyl bromides results in the formation of thioethers 6.

Page(s): 563-567

Chemical investigation of the marine sponges Clathria reinwardti and Haliclona cribricutis

Title: Chemical investigation of the marine sponges Clathria reinwardti and Haliclona cribricutis

Authors: Goud, T Venkateshwar; Krishnaiah, P; Reddy, S Malla; Srinivasulu, M; Rao, M Rama; Venkateswarlu, Y

Abstract: Diethylene glycol dibenzoate (DEGDB) (1) and two fenvalerate isomers (4 and 5) have been isolated from the sponges Clathria reinwardti and Haliclona cribricutis respectively. Two other diethylene glycol esters (2 and 3) are also synthesized. The structures of the compounds have been established by means of spectroscopic analysis, optical rotations and comparison with known compounds. These compounds are evaluated for their antimicrobial and pesticidal activities.

Page(s): 607-610