Indian Journal of Chemistry

Sect. B: Organic Chemistry including Medicinal Chemistry

VOL. 41B

NUMBER 10

OCTOBER 2002

CONTENTS

 

 

Rapid Communications

 

 

2109

Iodine mediated novel and facile dehydration of aldoximes to nitriles

Aldoximes can be induced to loose water to yield nitriles at room temperature by treatment with iodine in acetonitrile in excellent yields.

 

 

 

 

 

P Saikia, Md Ilias, D Prajapati & J S Sandhu*

 

 

 

 

 

 

 

 

 

 

2112

Michael addition of masked thiolates to conjugated systems in aqueous media promoted by ammonium tetrathiomolybdate

Thiolates generated in situ by the action of ammonium tetrathiomolybdate on alkyl halides, thiocyanates and disulfides undergo Michael addition to a,b-unsaturated esters, nitriles and ketones in water under neutral conditions

 

 

 

 

 

Naduthambi Devan, Devarajalu Sureshkumar,
Ian Beadham, Kandikere Ramaiah Prabhu &
Srinivasan Chandrasekaran
*

 

 

 

 

Advances in Contemporary Research

 

 

 

 

2116

Soluble polymer supported asymmetric synthesis (SPSAS)

Role of asymmetric catalysis in solid phase organic synthesis is described especially on the soluble polymer supports, namely, poly (ethylene glycol). The review focus only on the recent progress in this area. Some of advantages as well as limitations posed by this soluble polymer system is also described. The popular reactions covered in this review include asymmetric dihydroxylation, epoxidation, reductions and C-C bond formations.

 

 

 

Srivari Chandrasekhar, Jhillu S Yadav*, Jean-Claude Guillemin,
Pandarinathan Lakshmipathi & Rene Gree*

 

 

 

 

 

Papers

 

 

 

 

2129

Studies on the structure of 7a-hydroxytaraxerol

The proposed structure of the natural product 7a-hydroxytaraxerol (D-friedoolean-14-en-3b, 7a-diol) 1 has been established by its synthesis from multiflorenol (D : C-friedoolean-7-en-3b-ol) 2.

 

 

 

 

Kakoli Majumdar, Mahuya Roy & Saktipada Das*

 

 

 

 

 

 

 

 

 

2132

AlCl3-mediated transformation of 4-oxo-4H-1-benzopyran-3-carboxaldehyde

 

 

 

 

 

Chandrakanta Bandyopadhyay*, Kumar Ranabir Sur,
Ranjan Patra & Raja Banerjee

 

 

 

 

 

 

 

 

 

2136

Syntheses and structural elucidation of novel benzimidazolium dichromates obtained from simple benzimidazoles and chromium (VI) reagents

2-Alkylbenzimidazoles 2 react with chromium (VI) reagents, such as CrO3, K2Cr2O7, K2CrO4 and pyridinium dichromate, in aq. acetic acid at RT to yield beautifully coloured products which have been found to be benzimidazolium dichromates 4.

 

 

 

 

K Ramaiah, P K Dubey*, J Ramanatham,
C Ravi Kumar, J S Grossert, T S Cameron &
S V Sareda

 

 

 

 

 

 

 

 

2145

Substituent effects on the spontaneous cleavage of benzyl-gem-dichlorides in aqueous solution

The solvolysis reactions of benzyl-gem-dichlorides in water proceed by a stepwise mechanism through a-chlorohalobenzyl carbocation intermediates, which are captured by water to give the corresponding benzaldehydes as the sole detectable products.

 

 

 

R Sanjeev & V Jagannadham*

 

 

 

 

 

 

 

2150

Effect of a-halogen atom and a-azido group on thermodynamic stability and kinetic reactivity of benzyl carbocations in aqueous solution

There is a good relationship between equilibrium and rate constants for the formation (K) and reaction (ks, with water) of benzyl carbocations stabilized by a-halogen substituents and a benzyl carbocation stabilized effectively by an azido group deviated from this relationship. Thus for both the cases reasonable explanations are given.

 

X = Cl, Br, and

 

 

R Sanjeev & V Jagannadham*

 

 

 

 

 

 

 

2153

Kinetics and mechanism of oxidation of 4-oxoacids by hexacyanoferrate(III) catalysed by Os(VIII)

Kinetics of Os(VIII) catalysed oxidation of substituted and unsubstituted 4-oxoacids by alkaline hexacyano-ferrate(III) in sodium carbonate-bicarbonate buffer have been studied.

 

 

 

D Freeda Gnana Rani, F J Maria Pushparaj,
I Alphonse & K S Rangappa*

 

 

 

 

 

 

 

2160

Studies on butenolides: 2-Arylidene-4-(substi­tuted aryl)but-3-en-4-olides ¾ synthesis, reactions and biological activity

Synthesis of twenty three new butenolides, fourteen pyrrolones and five N-benzylpyrrolones is described. All the above compounds have been tested for their anti-inflammatory and antimicrobial activity. A few compounds show highly encouraging anti-inflammatory and antifungal activity.

 

 

 

 

M S Y Khan*, A Husain & S Sharma

 

 

 

 

 

 

 

 

2172

Synthesis and biological evaluation of glycolamide esters as potential prodrugs of some non-steroidal anti-inflammatory drugs

Ester prodrugs of common NSAIDs based on glycolamides reported in this paper show comparable anti-inflammatory and analgesic actions while the gastrointestinal toxicity is markedly reduced.

 

 

 

M S Y Khan* & R M Khan

 

 

 

 

 

 

 

2176

Synthesis and antibacterial activities of 1,3,4-oxadiazole derivatives containing 5-methyl-isoxazole moiety

5-(5-Methylisoxazol-3-yl)-4-substituted aminomethyl-2-thio-1,3,4-oxadiazoles 3a-e , 4-acetyl-2- (5-methyl­isoxazol-3-yl)-5-substituted-1,3,4-oxadiazoles 5a-c and 2-aryl-5-(5-methylisoxazol-3-yl)-1,3,4-oxadi-azoles 6a-c have been synthesized and their antibacterial activities evaluated.

 

 

 

Xin-Ping Hui, Chang-Hu Chu, Zi-Yi Zhang*, Qin Wang & Qi Zhang

 

 

 

 

Notes

 

 

 

2180

Synthesis of 2-nitroimino-1,3-diazacycloalkanes

An efficient, practical and enviro-friendly method of preparation of 2-nitroimino-1,3-diazacycloalkanes
3a-d has been reported with very good yields.

 

 

B China Raju & V Jayathirtha Rao*

 

 

 

 

 

 

 

 

2182

Synthesis of 1, 5-substituted-s-triazolinodino [1,2-a]-s-triazolidine-3,7-dithione and 1,2,4-triazolidine-3-thione derivatives from azines

Azines 1a-h react with ammonium thiocyanate in the presence of acetic acid to give 1,5-substituted-s-triazolinodino[1,2-a]-s-triazolidine-3,7-dithione 2a-e and 1, 2, 4-triazolidine-3-thione 2f-i derivatives.

 

 

 

 

Harish Kumar*, Rita Goyal, Sukhwinder Kaur, R D Anand, Anupama Parmar & Baldev Kumar

 

 

 

 

 

2185

One-pot synthesis of antimalarial drug
artemether from artemisinin

A one-pot, Amberlyst-15 mediated, high yield synthesis of antimalarial drug artemether 2 from artemisinin 1 is described.

 

 

Chandan Singh* & Pallavi Tiwari

 

 

 

 

 

 

 

2187

trans-Stereoselective addition of iodonium
nitrate to substituted chalcones

Nitrate iodination of substituted chalcones (1, 4 and 7) with iodonium nitrate (generated in situ) furnishes two isomeric products in each case on TLC. Of these, trans–stereoselective products (2, 5 and 8) are major since SN2 reaction is more favourable than SN1 reaction.

 

 

 

 

Naseem Ahmed & W H Ansari*

 

 

 

 

 

 

 

 

 

2190

Steric and electronic effects in catalytic epoxidation of cis(trans)-stilbenes and R-limonene with Mn(porphyrin)OAc-NaIO4 systems

Conversion, stereoselectivity, and regioselectivity of epoxidations are affected by the presence of imidazole and substituents on the periphery of porphyrin and alkene.

 

 

 

Reza Tayebee

 

 

 

 

 

 

 

 

 

 

2194

Microwave assisted Claisen-Schmidt condensation under solvent-free conditions

Microwave assisted Claisen-Schmidt condensation of 3 with aromatic aldehydes under solvent-free conditions to prepare a,b-unsaturated ketones 4 using solid KOH as catalyst is reported.

 

 

 

K Mogilaiah* & G Kankaiah

 

 

 

 

 

 

 

 

 

 

2197

Synthesis of monomethylated dimeric benzo-pyrans as HIV-1 and HIV-2 inhibitors:
Part I

Monomethylated dimeric coumarins have been synthesized by condensation of 6- or 8-methyl-4-hydroxy-coumarins with different aromatic aldehydes. Twenty three compounds of the two series have been screened for anti-HIV activity against HIV-1 and HIV-2 strains.

 

 

 

Mausami Chavda, Denish Karia &
Anamik Shah*

 

 

 

 

 

 

 

 

 

 

2200

Lanosta-8,17, 25-trien-3b-ol and isomeric trichlorotrimethoxybenzenes from Fomes fastuosus

A new triterpene 1 along with two isomeric trichlorotrimethoxybenzenes 2 and 3 have been isolated and characterized from Fomes Fastuosus

 

 

 

Subhash C Jain*, Ravindra Kumar,
Bhavna Gupta & Carl E Olsen

 

 

 

 

 

 

 

Authors for correspondence are indicated by (*)