نتایج جستجو برای: preparation of acid chlorides
تعداد نتایج: 21224005 فیلتر نتایج به سال:
A metal-free chemodifferentiating A2BB' 4CR manifold for the modular synthesis of tertiary skipped diynes is described. The manifold performs a triethylamine triggered reaction of alkyl propiolates and acid chlorides to assemble two units of each component in the form of two propargylic alkynoates, a tertiary alcohol, and an ester. A differentiated incorporation of the two acid chloride compone...
We describe the palladium-catalyzed multicomponent synthesis of 2-imidazolines. This reaction proceeds via the coupling of imines, acid chlorides and carbon monoxide to form imidazolinium carboxylates, followed by a decarboxylation. Decarboxylation in CHCl(3) is found to result in a mixture of imidazolinium and imidazolium salts. However, the addition of benzoic acid suppresses aromatization, a...
A new series of 5-substituted-3-methylsulfanyl-1-(2,4-dinitro phenyl)-1H-pyrazole-4-carboxylic acid ethyl esters were synthesized by reacting the amino group of 5-amino-3-methylsulfanyl-1-(2,4-dinitro phenyl)-1H-pyrazole-4carboxylic acid ethyl ester with acid anhydrides, acid chlorides and phenyl dithiocarbamates. The title compounds were investigated for analgesic, anti-inflammatory and ulcero...
The selective α,α-difluorination of carbonyl compounds remains a challenge in modern organic synthesis; current methods often incorporate stepwise processes and/or harsh conditions, providing unsatisfactory mixtures of mono- and difluorinated products. In this communication, a practical, mild, and one-pot method for the selective α,α-difluorination of readily available acid chlorides is reporte...
Ionic liquids consisting of a phosphonium cationic moiety and a saccharinate anion are synthesized and compared with their precursors, phosphonium chlorides, in reference to their extraction efficiency towards L-lactic acid. On the base of measurements of the acid and the water partitioning in the equilibrium biphasic systems, the molar ratios between acid, water and ionic liquid are estimated ...
S U M M A R Y The method of digestion with pancreatic lipase for determining the position of fatty acids in triglycerides has been modified to increase its accurary and ease of applicability. Moreover, by acylation of partial glycerides with a “marker” fatty acid, the method can be used for determining the structure of monoand diglycerides. Evidence is presented which demonstrates that acylatio...
A quick, efficient, one-pot method for the synthesis of substituted N-aryl lactams through the reaction of various kinds of corresponding substituted arenes with a variety of ω-azido alkanoic acid chlorides using a Lewis acid (i.e. EtAlCl(2)) at room temperature, through the in situ involvement of a Friedel-Crafts reaction followed by intramolecular Schimdt rearrangement was developed, and affo...
We report a new method for the catalytic, asymmetric synthesis of beta-substituted aspartic acid derivatives in which the nucleophilic catalyst serves up to four discrete roles in a one-pot procedure: catalytic dehydrohalogenation of acid chlorides to form ketenes; catalytic dehydrohalogenation of alpha-chloroamines to form the corresponding imines; catalyzed [2 + 2]-cycloaddition to produce in...
The development of an enantioselective catalytic Claisen rearrangement1 remains an important yet elusive goal in chemical synthesis.2 With this objective in mind, we recently reported the acyl-Claisen rearrangement, a Lewis acid-catalyzed variant of the Bellus reaction3 that utilizes acid chlorides and allylic amines in the stereoselective synthesis of R,â-disubstituted-γ,δ-unsaturated carbonyl...
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