Large-Scale Synthesis of a Pyrrolo[2,3-<i>d</i>]pyrimidine via Dakin−West Reaction and Dimroth Rearrangement
作者:Reto W. Fischer、Marian Misun
DOI:10.1021/op010041v
日期:2001.11.1
Pyrrolo[2,3-d]pyrimidines have been widely investigated as pharmaceutically active compounds. In this article, we present a short and efficient synthesis of 4-(3-chlorophenylamino)-5,6-dimethyl-7H-pyrrolo[2,3-d]pyrimidine starting from cheap alanine and malononitrile. To the best of our knowledge, the first application of a Dakin−West reaction on plant scale is demonstrated by elaboration of a modified
Three-component condensation of 5-aminoimidazole derivatives with aldehydes and Meldrum’s acid. Synthesis of 3,4,6,7-tetrahydroimidazo[4,5-b]pyridin-5-ones
作者:B. V. Lichitsky、A. N. Komogortsev、A. A. Dudinov、M. M. Krayushkin
DOI:10.1007/s11172-012-0211-6
日期:2012.8
method for the synthesis of the earlier unknown substituted 3,4,6,7-tetrahydroimidazo[4,5-b]pyridin-5-ones was developed based on a three-component condensation of 5-aminoimidazole derivatives, aldehydes, and Meldrum’s acid. Unstable aminoimidazole derivatives were readily formed in situ by decarboxylation of 5-amino-4-imidazolecarboxylic acids in acidic medium at room temperature, whose sodium salts were
The desymmetric dicarbofunctionalization of unactivatedalkenes by a nickel-catalyzed reductive cross-coupling reaction has been developed to access pyrrolidinones bearing multi-stereocenters with broad functional-group tolerance. The utilization of the 8-Quinox ligand is crucial for maintaining high enantio- and stereoselectivities.
A series of new isoniazid hydrazones was synthesized by two procedures. In the first isoniazid was activated with diethoxymethyl acetate and condensed with the appropriate anilines. Alternatively, substituted anilines were activated by diethoxymethyl acetate and subsequently condensed with isoniazid. NMR study confirmed that both synthetic approaches gave the same tautomer. All compounds were screened for in vitro antimycobacterial activity. Most of them exhibited the same activity against Mycobacterium tuberculosis (MIC 1 mu mol L-1) as isoniazid (INH), better activity against Mycobacterium kansasii 325/80 (MIC 0.125-0.250 mu mol L-1), high value of selectivity index (SI) and IC50 between 0.0218 and 0.326 mmol L-1. Compound 2o with the best SI was used as a model compound for the stability test and was found to be stable at neutral pH, but under acidic conditions it slowly hydrolysed. (C) 2011 Elsevier Masson SAS. All rights reserved.