Vidavalur Siddaiah

PEG-Mediated Catalyst-Free Synthesis of Hantzsch 1,4-Dihydropyridines and Polyhydroquinoline Derivatives

Abstract Hantzsch 1,4-dihydropyridines and polyhydroquinoline derivatives were synthesized in good yields by PEG-mediated, catalyst–free synthesis under solvent-free conditions. The products were directly recrystallized from hot methanol. The reaction gave excellent yields with low- as well as high-molecular-weight polyethylene glycols. GRAPHICAL ABSTRACT

Practical Synthesis of 4-Benzylidene-2-phenyl-5(4H)-oxazolones

Abstract A simple and alternative method has been developed for the synthesis of 4-benzylidene-2-phenyl-5(4H)-oxazolones via reactions of hippuric acid with various aldehydes in the presence of 2-chloro-4,6-dimethoxy-1,3,5-triazine/N-methylmorpholine at 75 °C. Supplemental materials are available for this article. Go to the publishers online edition of Synthetic Communications® to view the free supplemental file. GRAPHICAL ABSTRACT

Facile One-Pot Synthesis of 8H-Quinazolino[4,3-b]Quinazolin-8-Ones

Abstract A new, facile, one-pot synthesis of 8H-quinazolino[4,3-b]quinazolin-8-ones starting from the readily available 2-aminobenzonitriles, dimethylformamide-dimethylacetal, and anthranilic acid/esters in good yields is presented. GRAPHICAL ABSTRACT

Polyethylene glycol mediated facile protocol for N-Cbz protection of amines

Abstract We have reported an efficient and eco-friendly protocol for the protection of various structurally and electronically divergent aryl and aliphatic amines using Cbz-Cl in the presence of polyethylene glycol (PEG)-400 at room temperature. The reaction afforded excellent yields with low as well as high molecular weight PEGs.

One pot oxidative dehydration - oxidation of polyhydroxyhexanal oxime to polyhydroxy oxohexanenitrile: A versatile methodology for the facile access of azasugar alkaloids

A unique oxidative dehydration-oxidation of polyhydroxy-oxime (7) to the corresponding ketonitrile (8) in one pot is reported for the first time in carbohydrate literature. Key ketonitrile intermediate (8) upon palladium hydroxide mediated cascade reaction afforded 1-deoxynojirimycin (DNJ) 1b in moderate diastereoselectivity. The cascade reaction involves the conversion of nitrile to amine, heteroannulation, reduction of the imine and subsequent debenzylation to furnish the azasugars. This oxidative dehydration-oxidation and reductive heteroannulation methodology is successfully utilized for the total synthesis of 1-deoxynojirimycin (1b), miglitol (2) and miglustat (3).

Successful utilization of \(\upbeta \)-ketonitrile in Biginelli reaction: synthesis of 5-cyanodihydropyrimidine

A Biginelli reaction of β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}

Sulfonic acid–functionalized Wang resin (Wang-OSO3H) as polymeric acidic catalyst for the ecofriendly multicomponent synthesis of polyhydroquinolines via Hantzsch condensation

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Brønsted acid-catalyzed simple and efficient synthesis of 1,2,4-triazoles and 1,2,4-oxadiazoles using 2,2,2-trichloroethyl imidates in PEG

\end{document}-ketonitriles, aldehydes and urea in principle can yield 5-cyano substituted dihydropyrimidinones. Although potentially very useful, this substituted heterocycle is often difficult to synthesize via the three component reaction, presumably due to the lack of stability of β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}