127

Attempt towards [2.2](2,4)anti-thiazolo­phane: Synthesis and conformational analysis of the key intermediate lactone-bridged thiazolophane

Sabir H Mashraqui* & Sushma S Lele

132

BF₃ etherate-induced formation of C₇-C₁₆-alkyl b-d glucopyranosides

BF₃ etherate-induced formation of C₇-C₁₆-alkyl d-gluco­pyranosides is used as the key step in their synthesis from glucose and C₇-C₁₆-alkanols.

a) Ac₂O, NaOAc b) ROH (3), BF₃.Et₂O

c) MeOH:Et₃N:H₂O

Zorica Petrovic, Stanimir Konstantinovic* & Aleksandra Spasojevic

135

Synthesis of fused dihydropyrimidinones from cyclic-1,3-dicarbonyl compounds : Modi­fied Biginelli synthesis of 1,2,3,4,5,6,7,8-octahydroquinazolinediones and 3,4-dihydro-1 H-indeno[1,2-d] pyrimidine-2,5-diones

Syntheses of bicyclo-3,4-dihydropyrimidinediones from cyclic 1,3-diketones such as 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and 1,3-indanedione have been effected with good selectivity under microwave irradiation.

Pachaiyappan Shanmugam, Cruz Sabastein & Paramasivan T Perumal*

141

Synthesis of novel 2-(5¢-substituted-2¢-phenylindole-3¢-yl)-5-(coumarin-3¢¢-yl)-1,3,4-oxadiazoles and 4-(5¢-substituted-2¢-phenyl­indole-3¢-yl)- 1-(coumarin-3¢¢-amido)azetidin-2-one and their antimicrobial activity

The title compounds have been synthesised from 5-substi­tuted-2-phenylindol-3-carboxaldehydes and screened for their antimicrobial activity

J S Biradar* & S Y Manjunath¹

144

Semiempirical PM3 calculations of pyridinium dichlorophosphinomethylides: Presence of negative hyperconjugation

                                                  A                                                TS_rot.                                                 B

Raj K Bansal*, Neelima Gupta & Sarita Bansal

149

Kinetics of oxidation of ethylenediaminetetra­acetic acid (EDTA) by chromium(VI) in the presence of perchloric acid

Purple colour, l_max=400 and 550 nm

Zaheer Khan*, Raju & Kabir-ud-Din

157

Synthesis and psychotropic evaluation of some new N-substitutedbenzothia/oxazepinyl­phenothiazines

Several new N-[2-substitutedaryl-2,3-dihydro-1, 5-benzo­thia/oxazepin-4-yl]pheno­thiazines and N-[2-substi­tuted­aryl-3-substitutedarylaminomethylene-2,3-dihydro-1,5-ben­­zo­thia/oxazepin-4-yl]phenothiazines have been synthe­si­zed and evaluated for their psychotropic activity.

Kiran Bajaj, V K Srivastava &

Ashok Kumar*

162

Synthesis of biscoupled hemin-thiazoline derivatives and their anticancer activity evaluation

A number of biscoupled hemin-thiazoline deri­va­tives have been synthesized and evaluated for anti­cancer activity.

Sham M Sondhi*, Monika Johar,
Nirupma Singh & Sunanda G Dastidar

168

Synthesis of isoxazolylpyrazolo[3,4-d]thia­zoles and isoxazolylthiazoles and their antibacteial and antifungal activity

A series of substituted[2-(2,4-dinitrophenyl)-6-(3-methyl-5-styryl-isoxazol-4-yl)-3-aryl-2, 3,3a, 6-tetrahydro­pyra­zolo­[3,4-d]thiazol-5-ylidene]-methyl/phenyl amines 5, substi­tuted methyl/phenyl[3-(3-methyl-5-styryl-isoxazol-4-yl)-4-phenyl-3H-thiazol-2-ylidene]amines 6 and substituted methyl / phenyl [3-(3-methyl-5-styryl-isoxazol-4-yl) thia­zo­li­din-2-ylidene]amines 7 have been synthesized starting from 1-methyl / phenyl-3-(3-methyl-5-styryl-isoxazol-4-yl)thioureas 2. All the compounds have been evaluated for their antibacterial and antifungal activity.

E Rajanarendar*, Md Afzal & D Karunakar

174

Synthesis and antimicrobial activities of some imidazole substituted indoles

Some 1-substituted 2-(imidazol-1-yl)-3-(4,5-diarylimid­azol-2-yl)indoles 2, 1-substituted 2-(imidazol-1-yl)-3-(phenanthro[9,10-d]imidazol-2-yl)indoles 3, 1-substi­tuted 2-(imidazol-1-yl)-3-(benzimidazol-2-yl)indoles 4 have been synthesised from 1. Antimicrobial activities of the compounds are examined.

Kadriye Benkli*, Seref Demirayak,
Nalan Gundogdu-Karaburun, Nuri Kiraz, Gokalp Iscan & Umit Ucucu

180

Thiadiazolyl quinazolones as potential antiviral and antihypertensive agents

Phthalic anhydride on treatment with b-ethanol amine gives N-hydroxyethyl phthalimide 1 which reacts with anthranilic acid in presence of ethanol containing concentrated hydrochloric acid affording 5-(N-ethyl­phthalimido)anthranilic acid 2. This on treatment with benzoyl chloride in pyridine gives 6-(N-ethylphthal­imido)-2-phenyl-4-oxo-3, 4-dihydrobenzoxazine 3 which on reaction with 2-amino-5-aralkyl-1, 3, 4-thiadiazoles 4 in pyridine results in the formation of 6-(N-ethyl­phthalimido)-3-[2¢-(5¢-aralkyl-1¢, 3¢, 4¢-thiadiazolyl)]-2-phe­nyl-4-oxo-(3H)-quinazolines 5.

184

Preparation and evaluation of some 1,3,4-thiadiazoles as diuretic agents

Sixteen newer 2-(substituted acetamido)-5-aryl-1,3,4-thiadiazoles have been prepared and screened for LD₅₀ and diuretic activity.

Sanmati K Jain* & P Mishra

Notes

189

A novel short synthesis of norbisabolide

A novel two-step synthesis of norbisabolide is reported involving free radical addition of diethyl malonate to (R)-(+)-limonene using cerium(IV) ammonium nitrate followed by hydrolysis and decarboxylation.

S B Solabannavar, P P Wadgaonkar,

Uday V Desai & R B Mane*

192

Hydrogenative cleavage of azo compounds catalyzed by commercial zinc dust using ammonium acetate

Azo compounds, both symmetrical and unsymmetrical are selectively and rapidly cleaved to corresponding amine/s by using commercial zinc dust and ammonium acetate in methanol at ambient pressure and temperature.

G R Srinivasa, K Abiraj &

D Channe Gowda*

196

Magnesium-induced pinacol coupling of aromatic aldehydes and ketones in water
under ultrasound

The pinacol coupling of aromatic aldehydes and ketones has been carried out in 20-62% and 10-91% yields, respectively with Mg and Mg-MgCl₂ in water under ultrasound irradiation at r.t. in 3-4hr.

Ji-Tai Li*, Yan-Jiang Bian, Shu-Ming Liu &
Tong-Shuang Li

199

Microwave assisted heterocyclization : A rapid and efficient synthesis of 1,5-benzothiazepines

1,5-Benzothiazepines 3 have been synthesized by a microwave promoted condensation of 2-aminothiophenol 2 and various chalcones 1 in the presence of catalytic amount of glacial acetic acid using N, N-dimethyl­formamide as a reaction mediator.

V M Patel* & K R Desai

202

Electron impact mass spectroscopy (EI-MS) studies of primaquine derivatives

A mass spectral study on two new oxidative products of primaquine and their fragmentation schemes has been rationalized. The structure of these compounds 5,8-di- [4¢- amino-1¢-methylbutylamino]-6,7dihydroxyquinoline (PI) and n-n tri – (4¢-amino-1¢-methylbutylamine) (PII) are proposed on the basis of molecular and fragment ions. The fragment ions are obtained due to ring cleavages, rearrangement, and loss of side chain from the ring. In vitro studies carried out by us show that the PII has significant gametocytocidal activity almost similar to primaquine. But the schizontocidal activity of PII is more than primaquine. Therefore the spectra reported might serve as reference for the development of new molecules for the radical cure of relapsing malaria.

Sukesh N Sinha

207

Synthesis, CNS and chloroquin resistance reversal activity of benzenepropanamines

Several benzenepropanamines with a benzyl group attached to the 3-amino function have been synthesized and evaluated for their CNS and chloroquin resistant reversal activity. These compounds have been tested for their effect on gross behaviour and for antidepressant, anticonvulsant and anorexigenic activity.No effect is observed on gross behaviour whereas most of them show fluoxetine like antireserpine and anorexigenic acti­vity.Five compounds selectively inhibit P.falciparum heme oxygenase like fluoxetine.

V L Sharma, Kalpana Bhandari,
Girija Shankar, H K Singh ,
Pratima Srivastava & V C Pandey

212

Synthesis and antimicrobial activity of some benzazole derivatives

Thirteen new benzimidazole, benzoxazole and benzothiazole derivatives have been synthesized. Their structures are determined by the elemental analyses and spectral data (IR, ¹HNMR, EIMS). Antimicrobial activities are reported.

X= NH, O, S; R= H, CH₃, C₂H₅, C₆H₅; n= 1, 2; R₁= H, CH₃, F, Br, NO₂

N Karali*, N Cesur, A Gürsoy, Ö Ateş,  S Özden, G Ötük & S Birteksöz

217

A new eudesmanolide from Sphaeranthus indicus (Linn).

The structure and stereochemistry of compound 1 has been established by detailed spectral analysis and comparisons with reported compounds.

Ravindra B Jadhav, Kiran B Sonawane, Govind T Panse & Supada R Rojatkar*

219

5,8-Dihydroxy-6,7,4¢-trimethoxyflavone, a novel flavonoid constituent of Limnophila indica

Isolation and characterization of a new flavonoid compound, 5,8-dihydroxy-6,7,4¢-trimethoxyflavone 1, from the petrol extract of Limnophila indica has been reported.

G Brahmachari*, D Gorai, D Chatterjee, S Mondal & B Mistri

223

Isolation and characterization of selected secondary metabolites from dry leaves of Quercus semicarpifolia

Nonacosane, friedelin 1, b-sitosterol 2 and oleanolic acid 3 from petroleum ether; 5‑acetoxy-3,3¢,4¢,5¢-tetramethoxyflavone 4 from acetone and quercetin 5 from methanolic extract have been isolated from dry leaves of Quercus semicarpifolia.

S M S Chauhan*, Mamta Singh & Anil Kumar

Authors for correspondence are indicated by (*)