NISCAIR Online Periodicals Repository Collection: IJC-B Vol.44B(07) [July 2005]

Synthesis of potential fungicidal bibenzyls from bio-renewable source

Tue, 28 Jun 2005 22:58:59 GMT

Title: Synthesis of potential fungicidal bibenzyls from bio-renewable source

Authors: Siddiqui, Ibadur R; Singh, Jaya; Singh, Pravin K; Singh, Jagdamba

Abstract: Acetylation of bibenzyl 1 yields 4,4'-diacetylbibenzyl 2, which on condensation with different aryl amines gives corresponding Schiff’s bases in situ. Nucleophilic addition of 2-mercaptopropionic acid or 2-mercaptosuccinic acid on Schiff’s bases followed by cyclodehydration in solvent-free condition under microwave irradiation affords 4,4'-bis(3"-aryl-2"-methyl-5"-methyl/carboxymethyl-4"-oxo-thiazolidin-2"-yl)bibenzyl 3a-n with excellent yield (88-94%). The rate of the reaction is enhanced 225 times in comparison with conventional method. Antifungal screening results on Fusarium oxysporum and Penicillium citrinum show that most of the synthesized compounds display promising antifungal activity, comparable with Griseofulvin and Dithane M-45 as standards.

Page(s): 1460-1464

Chemoselective reaction of benz(g)indole based bisheterocycle dicarboxylate towards hydrazine hydrate: Synthesis and antimicrobial activity of new triheterocycles-5-pyrrolylaminocarbonyl/ mercaptooxadiazolyl/4-allyl-5-mercaptotriazolylmethoxy-1-furfuryl-2-methylbenz(g)indoles

Tue, 28 Jun 2005 22:58:59 GMT

Title: Chemoselective reaction of benz(g)indole based bisheterocycle dicarboxylate towards hydrazine hydrate: Synthesis and antimicrobial activity of new triheterocycles-5-pyrrolylaminocarbonyl/ mercaptooxadiazolyl/4-allyl-5-mercaptotriazolylmethoxy-1-furfuryl-2-methylbenz(g)indoles

Authors: Donawade, Dundappa S; Raghu, A V; Muddapur, U M; Gadaginamath, Guru S

Abstract: Chemoselectivity of C₅-ester over that of C₃-ester function of the benz(g)indole based bisheterocycle dicarboxylate towards the nucleophilic attack of hydrazine hydrate has been evidenced by the exclusive formation of 1-furfuryl-3-ethoxycarbonyl-5-hydroxy-2-methylbenz(g)indole-5-yloxyacetic acid hydrazide 5 which is reacted separately with acetonyl acetone, carbon disulphide in boiling ethanolic potassium hydroxide and allyl isothiocyanate to produce respectively 1-furfuryl-3-ethoxycarbonyl-5-(2,5-dimethylpyrrol-1-yl)aminocarbonylmethoxy-2-methylbenz(g)indole 7, 1-furfuryl-3-ethoxy-carbonyl-5-(5-mercapto-1,3,4-oxadiazol-2-yl)methoxy-2-methylbenz(g) indole 8, and 1-furfuryl-3-ethoxycarbonyl-5-(N-allylthiosemicarbazinocarbonyl)methoxy-2-methylbenz(g)indole 9. The thiosemicarbazide 9 when heated with 4% NaOH undergoes cyclisation with concomitant hydrolysis of C₃-ester group to yield 1-fufuryl-5-(4-allyl-5-mercapto-1,2,4-triazol-3-yl)methoxy-2-methylbenz(g)indole-3-carboxylic acid 10. The structures of newly synthesized compounds are confirmed on the basis of their spectral and analytical data and the compounds are also screened for their antibacterial and antifungal activities.

Page(s): 1470-1475

Enantiospecific synthesis of B-seco-nortaxanes from two molecules of carvone

Tue, 28 Jun 2005 22:58:59 GMT

Title: Enantiospecific synthesis of B-seco-nortaxanes from two molecules of carvone

Authors: Srikrishna, A; Kumar, P Praveen; Reddy, T Jagadeeswar

Abstract: Enantiospecific syntheses of B-seco-nortaxanes have been accomplished starting from the readily and abundantly available monoterperpene (R)-carvone. Carvone has been converted into both A-ring as well as C-ring derivatives of taxane and coupled with a two carbon unit.

Page(s): 1430-1436

Synthesis of 1,3,4-oxadiazoles carrying imidazole moiety

Tue, 28 Jun 2005 22:58:59 GMT

Title: Synthesis of 1,3,4-oxadiazoles carrying imidazole moiety

Authors: Frank, Priya V; Kalluraya, Balakrishna

Abstract: A new series of 1,3,4-oxadiazoline derivatives 5a-l have been obtained by cyclisation of various hydrazones 4 with acetic anhydride. The hydrazones 4 in turn are obtained by the reaction of appropriate carbonyl compound with 2-methyl-5-nitroimidazole-1-acethydrazide 3. The new products are characterized by spectral and analytical data. Most of the tested compounds show promising antibacterial and antifungal activity.

Page(s): 1456-1459