Indian Journal of Chemistry

Sect. B: Organic Chemistry including Medicinal Chemistry

VOL. 41B

NUMBER 7

JULY 2002

CONTENTS

 

 

Papers

 

 

1450

A new approach for the synthesis of pyrazoles via 1,3-dipolar cycloaddition of nitrile imines to acetyl acetone

The acetyl acetone 3 reacts smoothly with the nitrile imines 2 generated in situ by the catalytic dehydrogenation of diphenyl hydrazones 1 using chloramine-T affords a regioselective cycloadducts 5,6 in 59-78% and 6-8% yields, respectively.

 

 

 

K B Umesha, K Ajay Kumar & K M Lokanatha Rai*

 

 

 

 

 

 

 

 

 

1454

Photolabile groups for exocyclic amino and O6/N-1 lactam protection in oligonucleotide synthesis

o-Nitrobenzyloxycarboxyl (nCbz) for selective protection of exocyclic amino function of nucleosides (A, dG, C) and O6-protection with o-nitrobenzyl (nBzl) group is being reported.

 

 

 

Arvind Misra, Snehlata Tripathi & Krishna Misra*

 

 

 

 

 

 

 

 

 

1460

Interesting product formation during O-alkyla-tion and subsequent rearrangement of two building blocks of dibromotyrosine based natural products

The O-alkylation (allylation/propargylation) of 3,5-dibromo-4-hydroxybenzaldehyde 1 and the corresponding acetophenone 2 results in the formation aryl-aryl coupled product by loss of formyl groups, aryl-aryl ether and aryloxy acetone in addition to the expected O-allyl/propargyl ethers. While the thermal Claisen rearrangement of allyl ethers 1 and 2 furnishes the C-allyl products by loss of bromine, the propargyl ether 7 surprisingly resisted rearrangement and underwent oxidation to yield the corresponding carboxylic acid.

 

 

Uppuluri V Mallavadhani*, Anita Mahapatra, K Narasimhan & L D Sahoo

 

 

 

 

 

 

 

 

 

 

1467

Synthesis and microbiological action of new dipenicillins and dicephalosporins derived from asparagic acid

A new synthetic method of some b-lactamic antibiotics containing an asparagic acid residue is described which is based on the acylation of the 6-aminopenicillanic acid (6-APA) and of the 7-aminodesacetoxycephalo-sporanic acid (7-ADCA), respectively, by acid dichlorides of the N-(o,m,p)-nitrobenzoyl asparagic acids at low temperatures in nonaqueous medium. The structures of the newly synthesized compounds have been elucidated by means of elemental analysis and spectral data (IR, UV, NMR) and their antibacterial activity has been evaluated.

 

 

Cristina Băsu, Valeriu Şunel* & Camelia Şoldea

 

 

 

 

 

 

 

 

 

 

1472

Biotransformations, antibacterial evaluations of the sesquiterpenoids and diterpenoids

The biotransformations of terpenoids by using fungi A. niger, G.cingulata and antibacterial activities have been conducted.

 

 

 

 

M Rama Rao, U Venkatesham, K V Sridevi,
P Srinivasa Reddy, Kaiser Jamil &
Y Venkateswarlu*

 

 

 

 

 

 

 

 

 

 

1477

Synthesis of some antimicrobial pyranocarbazomycins

The diazotised solution of 6-aminocoumarin is condensed with 2-hydroxymethylenecyclohexanone in ethanol to give hydrazone 4, which is further cyclised with glacial acetic acid and hydrochloric acid to give pyranocarbazol-10-one 5. Wolf Kishner reduction of 5 followed by dehydrogenation yields pyranocarbazole 7.

 

 

 

 

V V Mulwad*, M B Dalvi & B S Mahaddalkar

 

 

 

 

 

 

 

 

 

 

1480

Synthesis of novel quinoxaline carboxylic acid derivatives for antimicrobial investigation

Some quinoxaline carboxylic acid and pyrrolo[3,4-d]-quinoxaline derivatives have been synthesized by various methods using 6,7-dimethylquinoxaline-2,3-dicar-boxylic acid anhydride as starting material.

 

 

 

 

M S A El-Gaby*, M M F Ismail, Y A Ammar,
M A Zahran & N A M Shmeiss

 

 

 

 

 

 

 

 

 

 

1486

Some reactions with quinoxaline-2,3-dicarboxy-lic acid anhydride: Novel synthesis of thieno-
[2,3-d]pyrimidines and pyrrolo[3,4-b]quinoxa-lines as antimicrobial agents

The reactivity of quinoxaline-2,3-dicarboxylic anhydride towards some heterocyclic amines has been investigated.

 

 

Y A Ammar, M M F Ismail, M S A El-Gaby* &
M A Zahran

 

 

 

 

 

 

 

1492

C3H4: Effect of fluorine substitution on structures

Molecular structures and stabilities of the lowest singlet states of the five most stable isomers on the C3H3F singlet potential energy surface, and of the lowest singlet and triplet states of various monofluoro-substituted carbenes, are studied by the MNDO method.

 

 

Rita Kakkar* & Bhabani S Padhi

 

 

 

 

 

 

 

1500

A novel triterpenoid saponin from Eryngium foetidum

 

 

Edet M Anam

 

 

 

 

Notes

 

 

 

1504

Studies in the synthesis and characterization of macrocycles based on N, N-dimethyl-4,4-me-thylenedianiline as the basic skeleton

Spectral data and reasons for high yield synthesis of 5 (47%) than 4 (14%) starting from 1 are discussed.

 

Lalit Sharma

 

 

 

 

 

 

 

1507

A facile synthetic approach to cyclic carbonates and thiocarbonates via dianion cyclization

Synthesis of 5, 6-diaryl-1, 3, 4, 7-dioxadiazopin-2-ones 3a-d and 5, 6-diaryl-1, 3, 4, 7-dioxadiazopin-2-thiones 4a-d are prepared in one-pot from vicinal dioximes via dianion intermediates in good yields.

 

 

 

M S Singh*, B K Singh & A K Singh

 

 

 

 

 

 

 

1510

Synthesis of chlorodiphenylgermanium dithiocarbamates

Thirteen chlorodiphenylgermanium dithiocarbamates of the general formula Ph2Ge(Cl)S2CNRR' have been prepared by the reaction of dithiocarbamates with the appropriate diphenylgermanium dichloride in 1:1 stoichiometry.

 

Ph2GeCl2 + R'RNCS2Na Ph2Ge(Cl)S2CNRR'

 

 

Han Dong Yin*, Yong Wang, Ru Feen Zhang & Cun Lin Ma

 

 

 

 

 

1513

Synthesis and microbial activity of new 1,4-benzothiazines bearing paracetamol moiety

5-Acetamido-2-hydroxyacetophenone 1 on condensation with aroyl/heteroyl chlorides gives the esters 2. The esters are converted to 1,3-propanediones 3 using B.V. transformation. The cyclocondensation of 3 with 2-aminobenzenethiols furnishes the title 1,4-benzo-thiazines 4.

 

L R Patil, S P Bondge, V E Bhingolikar &
R A Mane*

 

 

 

 

 

 

 

1516

Synthesis and bioactivities of chlorodiphenylgermanium heterocyclic carboxylates

The eight chlorodiphenylgermanium heterocyclic carboxylates 1-8 have been synthesized by the reaction of corresponding diphenylgermanium dichloride with heterocyclic carboxylates in 1:1 molar ratio.

 

 

 

Han Dong Yin*, Yong Wang & Cun Lin Ma

 

 

 

 

 

 

 

1519

Synthesis and reactions of some 3-aryl-2-thioxoquinazolin-4(3H)-ones

A series of 3-aryl-2-thioxoquinazolin-4(3H)-ones are prepared in good yields from the reactions of anthranilic acids, aromatic amines and carbon disulfide under basic conditions in one step.

 

 

G A El-Hiti*, M F Abdel-Megeed & T M Zied

 

 

 

 

 

 

 

1523

Deoxygenation of sulphoxides on irradiated TiO2 surfaces

Alkyl aryl sulphoxides and diphenyl sulphoxide are readily deoxygenated to their corresponding sulphides in the presence of irradiated TiO2 .

 

 

N Somasundaram & C Srinivasan*

 

 

 

 

 

 

 

 

1526

Thermal/microwave assisted synthesis of substituted tetrahydropyrimidines as potent calcium channel blockers

The synthesis of 6-methyl-4-substitutedphenyl-2-oxo/thioxo-1, 2, 3, 4-tetrahydropyrimidine-5-carboxy-lic acid ethyl esters 1a-h/ 2a-e is achieved when aromatic aldehydes, urea/thiourea and ethyl acetoacetate are condensed in presence of piperidine as catalyst.
2a-e give 6-methyl-4-substitutedphenyl-2-S-alkyl-1,4-di-hydropyrimidine-5-carboxylic acid ethyl esters 3a-h when heated with a suitable alkylating agent. Potent Ca2+ channel antagonistic activity has been found in some of the compounds synthesized.

(1a-h/2a-e : X= O; X = S) (3a-e ; R1 = Me, n-Butyl, Benzyl)

(R = H, 2-OH, 2-Me, 2-NO2, 3-NO2, 4-OMe, 3,4-(OMe)2; X = O or S)

 

 

Baldev Kumar*, Balbir Kaur, Jatinder Kaur, Anupama Parmar, R D Anand &
Harish Kumar

 

 

 

 

 

 

 

1531

A new method for the synthesis of dry diazonium nitrates in nonaqueous condition

 

Amines react with PEG-NO2 adduct in nonaqueous conditions to give dry arenediazonium nitrate in high purity and high yield.

 

Qingzhi Zhang*, Shensong Zhang, Xinming Liu, Jinming Zhang, Lijuan Xu & Yunqing Wang

 

 

 

 

 

 

 

1535

Triterpenoid and acetophenone glycosides from Cassia sophera

Two new glycosides 3b, 22b, 24, 29-tetrahydroxy olean-12-ene-3, 24-O-b-d-dixylopyranoside and 3-(2-hydroxy-3-methyl-3-butenyl) acetophen one-4-O-[b-d-arabinopyranosyl (13)]-O-b-d- galactopyranoside have been isolated from the heart-wood of Cassia
sophera
.

 

 

Rashmi Sanghi*, Punita Srivastava & J Singh

 

 

 

 

 

 

 

 

 

1540

Isolation and characterization of dehydrogoniothalamin from Goniothalamus umbrosus

Three major compounds dehydrogoniothalamin, goniothalamin and 5-acetoxygoniothalamin have been isolated and characterized from the roots of Goniothalamus umbrosus Sinclair. Goniothalamin and 5-acetoxy-goniothalamin have been previously reported from several Goniothalamus sp. However, dehydrogoniothalamin has not been reported so far.

 

 

 

 

 

Fasihuddin B Ahmad* & Laily B Din

 

 

 

 

 

 

 

 

 

 

 

1542

A novel g-lactone, eutypoid-A and other metabolites from marine fungus Eutypa sp.(#424) from the South China Sea

A new compound eutypoid-A (1) and other metabolites have been isolated from the mycelia of Eutypa sp. (#424) and their structures established by spectral analysis and GC / MS.

 

 

 

Yongcheng Lin*, Houjin Li, Guangce Jiang, Shining Zhou, L L P Vrijmoed & E B G Jones

 

 

 

 

 

 

Authors for correspondence are indicated by (*)