H.M. Sampath Kumar

Studies on novel D-ring substituted steroidal pyrazolines as potential anticancer agents.

An efficient and facile synthesis of 17-pyrazolinyl derivatives of pregnenolone and their evaluation as potential anticancer agents against various human cancer cell lines are reported. The scheme involves the transformation of the starting pregnenolone acetate into pregnenolone, conversion of pregnenolone to the corresponding benzylidine derivatives and finally the conversion of this derivative to the stable steroidal 17-pyrazoline. Various compounds 4b, 4c, 4e, 4f, 4h and 4j showed significant cytotoxic activity especially against HT-29, HCT-15, 502713 cell lines.

4β-[(4-Alkyl)-1,2,3-triazol-1-yl] podophyllotoxins as anticancer compounds: design, synthesis and biological evaluation.

A series of 4β-[(4-alkyl)-1,2,3-triazol-1-yl] podophyllotoxin derivatives were designed in silico, synthesised by employing click chemistry approach, and evaluated for cytotoxicity against a panel of human cancer cell lines (SF-295, A-549, PC-3, Hep-2, HCT-15 and MCF-7). Majority of the compounds proved to be more potent than etoposide and select compounds exhibited significant anticancer activity with IC50 values in the range of 0.001-1 μM. DNA fragmentation and flow-cytometric results reveals that 4β-[(4-alkyl)-1,2,3-triazol-1-yl] podophyllotoxin derivatives induce dose dependent apoptosis. Docking experiments showed a good correlation between their calculated interaction energies with the topoisomerase-II and the observed IC50 values of all these compounds.

Indium mediated allylation of CN compounds in aqueous media

Abstract Allylindium adds to a variety of tosyl and aryl hydrazones derived from aromatic aldehydes and ketones at ambient temperature in a DMF–H2O solvent system to afford homoallylic tosyl hydrazides and homoallylic hydrazines, respectively. Homoallylic hydroxylamines were isolated via addition of allylindium to aldonitrones.

Microwave Promoted Rapid Dehydration of Aldoximes to Nitriles on a Solid Support

Abstract Aldoximes undergo rapid dehydration with H2SO4/ SiO2 solid support, under microwave irradiation in dry media to afford nitriles in high yields. †IICT Communication No: 3645

A novel and efficient approach to mono-N-alkyl anilines via addition of grignard reagents to aryl azides

Mono-N-alkyl anilines were obtained in high yields within a short reaction time when various aromatic azides were reacted with alkyl magnesium halides at room temperature.

An Expedient and Highly Selective Conversion of Alcohols to Azides using a NaN 3 /BF 3 .Et 2 O System

Abstract Alkyl azides were prepared in good yields by treatment of allylic and benzylic alcohols with a molar equivalent of NaN 3 in the presence of BF 3 .Et 2 O in dioxane.

Synthesis of novel steroidal D-ring substituted isoxazoline derivatives of 17-oxoandrostanes

A facile synthesis of isoxazoline derivatives of 17-oxoandrostane at the side chain of D-ring is reported. The scheme involves the transformation of the starting dehydroepiandrosterone acetate (ketone) to the Knoevenegel product, reduction to the nitrile, and elimination to the carboxaldehyde. Cycloaddition of nitrileoxides across olefinic aldehyde intermediate led to the synthesis of novel side chain isoxazoline derivatives.

SIO2 CATALYSED EXPEDIENT SYNTHESIS OF E-3-ALKENOIC ACIDS IN DRY MEDIA

Aliphatic aldehydes with α-hydrogens and malonic acid undergo decarboxylative condensation on the surface of SiO2 when subjected to microwave irradiation generating βγ-unsaturated acids in high yields.

CLAY CATALYZED HIGHLY SELECTIVE O-ALKYLATION OF PRIMARY ALCOHOLS WITH ORTHOESTERS

Montmorillonite KSF catalyzes the selective O-alkylation of various primary allylic and benzylic alcohols when reacted with different orthoesters at room temperature to afford ethers in moderate to high yields.

Stereochemistry of 4-aryl-2-butanols from himalayan Taxus baccata

Abstract 4-(4′-Hydroxyphenyl)-2 R -butanol, 4-(3′,4′-dihydroxyphenyl)-2 R -butanol and 4-(3′-methoxy-4′-hydroxy- phenyl)-2 R -butanol have been isolated from the needles of Himalayan Taxus baccata . These two compounds have not previously been reported in stereospecific forms. Their stereochemistry has been determined by enzymatic reduction of their corresponding 2-butanones.