Papers

1098

Syn-axial steric and counter-ion coordination factors in the a-methylation of 6-membered cyclic esters

trans Decalin 2-ester A does not form an enolate on treatment with Ph₃CNa (ether)/MeI while the diester B forms an enolate. The enolate does not undergo 2-methylation unless a chelating agent (HMPT) is added.

S N Balasubrahmanyam* & K Jayaraj

1111

Synthesis and characterization of novel [60]fullerene material with photoluminence property

A novel type of soluble polysiloxane with pendent C₆₀ and carbazole moieties simultaneously has been synthesized and characterized.

Xinhong Li, Yuanyin Chen*, Pengfei Fang & Shuling Gong

1115

A new route for the convenient synthesis of 5-amino-6 - aryl-3-(5-aryl-1,3,4 -oxadiazol-2-yl)-5,6-dihydro-2-thioxo-1,3-thiazin-4-ones

L D S Yadav* & Sarvesh Singh

1119

Lipase catalysed regioselective esterification of protocatechuic aldehyde 

Protocatechuic aldehyde is acetylated using   acetic anhydride in presence of porcine pancreas lipase and two preparations of Rhizomucor miehei to give a mixture of 3-acetoxy and 3,4-diacetoxy derivatives in good yields. All the three lipases show better selectivity  towards formation of 3-acetoxy-4-hydroxybenzaldehyde than the diacetoxy and 4-acetoxy derivatives.

Soundar Divakar

1123

C₃H₄: Kinetics of interconversion of isomers

Thermochemical parameters in the interconversion of the C₃H₄ isomers have been determined. The kinetics of the interconversions is studied using the RRKM quantum statistical approach.

 ¢

Rita Kakkar*, Bhabani S Padhi & Ritu Garg

1132

Kinetics and mechanism of the ninhydrin reaction with dl-methionine in the absence and the presence of organic solvents

Effect of organic solvents on the reaction of ninhydrin with dl-methionine has been studied.

Kabir-ud-Din*, Manzoora Bano &
Iqrar A Khan

1137

Substituent and solvent effects on the UV/vis absorption spectra of 3-N-alkyl-5-carboxy uracils

Absorption spectra of ten 3-N-alkyl-5-carboxy uracils have been recorded in fourteen solvents in the range 200-400 nm. The absorption frequencies of carboxy carbonyl electronic transitions are correlated by dual substituent parameter (DSP) treatment involving both polar (s*) and steric (E_s or n_c) substituent constants. The effect of solvent polarity and solvent/solute hydrogen bonding interactions on the absorption spectra are interpreted by means of linear solvation energy relationships (LSER).

R= H, CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, i-C₄H₉,

s-C₄H₉,  n-C₅H₁₁, n-C₆H₁₃, c-C₆H₁₁

Nataša V  Valentić, Gordana S  Ušćumlić* &

Mirjana Radojković-Veličković

1141

Sydnone derivatives: Part X—Synthesis and pharmacological activity of some novel cyclohexenones and indazolinones

A new series of 3-aryl-4[1¢–ssubstituted-2¢-H,4¢,5¢-dihydro-4'-(3,4-methylenedioxyphenyl)-3'-oxo-indazolin-6'-yl] sydnones 5 have been prepared by the reaction of hydrazine derivatives with appropriate sydnone cyclohexenones 4. The new compounds are evaluated for antiinflammatory and analegesic activities.

Balakrishna Kalluraya*& M Abdul Rahiman

1149

Synthesis of 1,5-benzothia/oxazepines as potent neuroleptic agents

Several new 2-(4¢-oxo-2¢-substitutedaryl-thiazolidinyl)­imino­methyl-1,5-benzothia/oxazepin-4(5H)-ones and 2-(4¢ -oxo-3¢-chloro-2¢-substitutedaryl-azetidinyl)-imino-me­thyl-1,5-benzothia/oxazepin-4(5H)-ones have been synthesized and evaluated for their neuroleptic activity.

Kiran Bajaj, V K Srivastava & Ashok Kumar*

Notes

1156

Syntheses of 11b-fluorocholestan-3-one deri­va­tives

Tej Vir Singh*, Jatinder Kapur,
Keshav Rai Agnihotri & Paloth Venugopalan

1159

Synthesis of fused cyclopentano and pyridino derivative incorporating pyridoquinoline compound

New fused heterocyclic compounds of cyclopentano derivatives have been obtained by the reaction of 2,3,7,8-tetra­hydropyrido[2,3-g]-4,5,9,10-tetraone quinoline (1H,6H)
1 with acrylonitrile derivatives.

H A Soleiman*, A K Khalafallah & H A Shindy

1165

Sulfuric acid supported on silica gel: An efficient catalyst for silylation of hydroxyl groups with HMDS and their convenient deprotection under non-aqueous condition

An easy silylation of alcohols and phenols with hexamethyldisilazane (HMDS) and convenient desilylation of silyl ethers are achieved using a catalytic amount of silica gel supported sulfuric acid under non-aqueous condition.

M M Lakouraj* & A Akbari

1168

Tetravalent metal acid salts: Solid acid catalysts for hydration of nitriles to amides

Metal(IV) phosphates of tin, titanium and zirconium catalyzed hydration of nitriles to the corresponding amides in moderate to high yield is reported

Sonal M Patel, Uma V Chudasama &
Pralhad A Ganeshpure*

1170

PTSA-catalyzed Friedlander condensation in the solid state

Friedlander condensation of 2-aminonicotinaldehyde 1 with active methylene compounds 2 to give 1, 8-naph­thyridines 3 is found to proceed very smoothly in the presence of PTSA in the solid state.

K Mogilaiah* & G Rama Sudhakar

1172

2-Methoxy-5-methylphenylthiosemicarbazide: A versatile molecule for the synthesis of thiadiazoles and imidazolinones possessing multiple biological activities

Preparation of 1,3,4-thiadiazoles 2a-o and imidazolinones 3a-o from 2-methoxy-5-methylphenylthiosemicarbazide 1, has been reported. All the compounds have been screened for their antimicrobial,  anticancer and antitubercular activity.

S B Hirpara, K A Parikh, B C Merja  &
H H Parekh*

1176

Bridgehead nitrogen spiroheterocyclic systems: Synthesis, stereochemistry and antimicrobial activity of spiro [(1¢R)-bicyclo­[2.2.1] heptane-2¢, 3 - (4¢H) - [2H]-thiazolo-[3,2-b]-s-tetrazines] and spiro[(1¢R) – bicyclo - [2.2.1]heptane - 2¢,3-(4¢H)-[2H] – pyrazolo- [3¢,4¢ : 4,5]-thiazolo[3,2-b]-s-tetrazines]

The synthesis of (1¢R)-6-(p-bromophenyl)-1¢,7¢,7¢-trime­thyl­­­spiro­[bicyclo[2.2.1] heptane-2¢,3-(4H)-[2H]-thiazolo­[3,2-b]-s-tetrazine]hydrobromide 2 and (1¢R)-1,2,4,5-tetra­­hydro-1¢,7¢,7¢-trimethyl­spiro [bicyclo[2.2.1]heptane-2¢,3-(4H)-[2H]-thiazolo[3,2-b]-s-tetra­zine]-6(7H)-one 3 have been accomplished by the reaction 1 with p-bromophena­cyl bromide and chloroacetic acid respectively.

2                                                   1                                           3

Jag Mohan

1180

New nor friedelene-1,3-dione from  the root bark of Salacia oblonga

A new nor friedelene-1,3-dione, identified as 15a-hydroxy-24-nor-friedel-5-ene-1,3-dione, has been isolated from the hexane extract of the root bark of Salacia oblonga.

S J  Anu & J Madhusudana Rao*

1183

Stigma-5-en-3a-O-(a-d-glucopyranoside), a new steroidal glycoside from Euphorbia geniculata Linn

A new steroidal glycoside stigma 5-en-3a-O-(a-d-glucopyranoside) 1 designated as geniculatoside D has been isolated from the aerial parts of Euphorbia geniculata Linn.

Abdul Rahman, Bahar Ahmed, Mohammed Ali, Najm Zaheer Khan*

1187

A minor pseudoguaianolide from the aerial parts of Parthenium hysterophorus L.

Padma Acharyya & Nabin C Barua*

1190

Revised structure for spatozoate, a metabolite of Spatoglossum variabile

Structure of spatozoate has been revised to 2 from 1 by synthesis. NMR data of synthetic 2 agrees well with that of natural metabolite.

Kur-Ta Cheng, Dodda Rajasekhar,
Sheng-Tung Haung, Feng-Lin Hsu & Gottumukkala V Subbaraju*

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