CuFe2O4Nanoparticle Mediated Method for the Synthesis of 5-Substituted 1H-Tetrazoles from (E)-Aldoximes
作者:Ravi Kumar Akula、Chandra S. Adimulam、Sathaiah Gangaram、Raju Kengiri、Narsaiah Banda、Shanthan R. Pamulaparthy
DOI:10.2174/1570178611666140210213157
日期:2014.4
A strategy for the synthesis of 5-substituted 1H-tetrazoles from various (E)-aldoximes and sodium azide was
adopted using copper ferrite nanoparticles as a reusable catalyst.
A novel method for the synthesis of 5-substituted 1H-tetrazoles using diphenyl phosphorazidate (DPPA) has been developed. Aromatic and aliphatic aldoximes underwent cycloaddition to afford the corresponding 5-substituted 1H-tetrazoles with ease and efficiency.
Highly Efficient Synthesis of 5-Substituted 1H-Tetrazoles Catalyzed by Cu-Zn Alloy Nanopowder, Conversion into 1,5- and 2,5-Disubstituted Tetrazoles, and Synthesis and NMR Studies of New Tetrazolium Ionic Liquids
作者:Gopalakrishnan Aridoss、Kenneth K. Laali
DOI:10.1002/ejoc.201100957
日期:2011.11
synthesize several novel tetrazolium ionic liquids (ILs) with EtSO4–, OTf–, and NTf2– counterions. Whereas alkylation of the 2,5-dialkyltetrazoles selectively gave the N-4 alkylated onium salts, with the 1,5-dialkyl derivatives approximately 1:1 mixtures of two tetrazolium salts were formed by alkylation at N-3 and N-4. The triflate and ethyl sulfate salts are room-temperature ILs that are hydrophilic, whereas
racemization. 5-Substituted 1H-tetrazoles were effectively synthesized from aldoximes and diphenyl phosphorazidate (DPPA) under reflux conditions in xylenes. Various aldoximes underwent the cycloaddition reaction to afford the corresponding 5-substituted 1H-tetrazoles in short reaction times and in good yields. Chiral aldoximes derived from amino acids also gave aminotetrazoles with almost no racemization.
This invention provides cholesterol absorption inhibitors of Formula I:
and the pharmaceutically acceptable salts thereof, wherein R
12
is an alkyl, alkeny or alkynyl group mono- or poly-substituted with —OH, —COOH or a combination of —OH and —COOH, and R
9
contains an alkyl, alkeny or alkynyl group substituted with a heterocyclic ring, amino or sulfonyl. The compounds are useful for lowering plasma cholesterol levels, particularly LDL cholesterol, and for treating atherosclerosis and preventing atherosclerotic disease events.