515-40-2Relevant articles and documents
Long sought synthesis of quaternary phosphonium salts from phosphine oxides: Inverse reactivity approach
Vetter, Anna C.,Nikitin, Kirill,Gilheany, Declan G.
supporting information, p. 5843 - 5846 (2018/06/13)
Quaternary phosphonium salts (QPS), a key class of organophosphorus compounds, have previously only been available by routes involving nucleophilic phosphorus. We report the realisation of the opposite approach to QPS utilising phosphine oxides as the electrophilic partner and Grignard reagents as nucleophiles. The process is enabled through the crucial intermediacy of the derived halophosphonium salts. The route does not suffer from the slow kinetics and limited availability of many parent phosphines and a broad range of QPS were prepared in excellent yields.
Visible Light-Induced Oxidative Chlorination of Alkyl sp3 C-H Bonds with NaCl/Oxone at Room Temperature
Zhao, Mengdi,Lu, Wenjun
supporting information, p. 4560 - 4563 (2017/09/11)
A visible light-induced monochlorination of cyclohexane with sodium chloride (5:1) has been successfully accomplished to afford chlorocyclohexane in excellent yield by using Oxone as the oxidant in H2O/CF3CH2OH at room temperature. Other secondary and primary alkyl sp3 C-H bonds of cycloalkanes and functional branch/linear alkanes can also be chlorinated, respectively, under similar conditions. The selection of a suitable organic solvent is crucial in these efficient radical chlorinations of alkanes in two-phase solutions. It is studied further by the achievement of high chemoselectivity in the chlorination of the benzyl sp3 C-H bond or the aryl sp2 C-H bond of toluene.
Regio-selective synthesis of key intermediates of fexofenadine
Kumar, Anil,Bhashkar, Bhuwan,Kumar, Harish,Singh, Gurpreet
, p. 2285 - 2287 (2015/12/19)
The present work is focused on improved process of preparation of fexofenadine which is achieved by regio-selective synthesis of intermediate; 1-oxoalkoxy-2-methyl-2-[4-(4-chloro-1-oxobutyl)phenyl]propane. The said intermediate is prepared in good yields and with greater purity wherein the synthesis of side products like 1-oxoalkoxy-2-methyl-2-[3-(4-chloro-1-oxobutyl)phenyl]propane (metaisomer) is reduced to a great amount. The intermediate, 1-oxoalkoxy-2-methyl-2-[4-(4-chloro-1-oxobutyl)phenyl]propane (para-isomer) where, alkyl group is selected from C2-5 carbon chain, is synthesized through preparation of 1-chloro-2-methyl-2-phenylpropane which upon reaction with potassium salt of aliphatic carboxylic acid followed by Friedel-Crafts acylation with 4-chlorobutyrylchloride results into desired intermediate, 1-oxoalkoxy-2-methyl-2-[4-(4-chloro-1-oxobutyl)phenyl]propane and a side impurity, 1-oxoalkoxy-2-methyl-2-[3-(4-chloro-1-oxobutyl)phenyl]propane (meta-isomer) in the ratio of 1:0.09-0.15. The above said mixture can be directly used for the synthesis of fexofenadine and has an advantage of eliminating the purification process at intermediate stage and use of less volume of expensive solvents.
