One-pot sequence synthesis of azetidin-2-one using diethyl chlorophosphate
A simple and convenient synthesis of 2-azetidinone derivatives from the reaction of a pre-mixture of amines and aldehydes with carboxylic acids in the presence of diethyl chlorophosphate by [2+2] cycloaddition reaction is described. Separation and purification of imines as intermediates were not required. The methodology is convenient and good to excellent yields of products were obtained with simple purification.
Zarei, Maaroof
experimental part
p. 118 - 120
(2012/05/04)
GREEN SYNTHESIS OF ARYL ALDIMINES USING ETHYL LACTATE
The present invention relates to a method for preparing aryl aldimines. In particular, the present invention relates to methods of preparing aryl aldimines that uses environmentally friendly solvent systems.
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Page/Page column 5-6
(2011/08/22)
Synthesis of structurally diverse 2-azetidinones via staudinger reaction on a solid support
Trimellitic anhydride was attached to Merrifield resin and a ketene was generated from polymer-bound phthaloylglycine. Then this polymer reacted with imines in the presence of Vilsmeier reagent and triethylamine to afford the solid-phase-tethered β-lactam products. Selective cleavage of supported β-lactams by trifluoroacetic acid and methylhydrazine gave 4-carboxyphthalimido- and 3-amino-β-lactams, respectively. The trans-stereochemistry was found in all products.
The Vilsmeier reagent: a useful and versatile reagent for the synthesis of 2-azetidinones
(Chloromethylene)dimethylammonium chloride (Vilsmeier reagent), prepared easily from N,N-dimethylformamide and oxalyl chloride or thionyl chloride, works as a versatile acid activator reagent for the direct [2+2] ketene-imine cycloaddition of substituted
Jarrahpour, Aliasghar,Zarei, Maaroof
experimental part
p. 2927 - 2934
(2009/05/30)
Synthesis of novel N-(4-ethoxyphenyl) azetidin-2-ones and their oxidative N-deprotection by ceric ammonium nitrate
It is shown that the N-(p-ethoxyphenyl) group on β-lactams can be oxidatively removed by ceric ammonium nitrate in good yield. Fourteen new N-(p-ethoxyphenyl)-2-azetidinones 8a-n were synthesized through standard [2+2] ketene-imine cycloadditions (Staudinger reaction). Treatment of these compounds with ceric ammonium nitrate yielded the N-dearylated 2-azetidinones 9a-n in good to excellent yields. The effects of solvent, molar equiv of CAN and different temperatures have been investigated and optimum conditions were established.
Jarrahpour, Aliasghar,Zarei, Maaroof
p. 2364 - 2379
(2008/02/14)
Study of binary systems inducing mesophase and determination of latent transition temperature
Five binary systems consisting of common component as nematogen (A), viz. p-(p'-n-propyloxybenzoyloxy)anisole is mixed with uncommon component (B) (nonmesogen or monotropic nematic), para-substituted Schiff bases, viz. X-C6H4-CH=N-C
Ganatra,Doshi
p. 322 - 325
(2007/10/03)
Thermodynamic Interpretation of the Terminal Group Effect on the Thermal Stability of a Mesophase
Nematic liquid crystal-isotropic liquid transition temperature-composition curves were calculated for the four binary systems between p-azoxyanisole and Shiff bases.The calculation was done by means of equal G analysis, which is one of the thermodynamic t
Araya, K.
p. 249 - 254
(2007/10/02)
Studies on Mixed Liquid Crystal. Part-I. Nemetic Mesophase induced by Mixing Two Non-liquid Crystalline Components and Determination of Latent Transition Temperature
Eight binary systems consisting of both non-liquid crystalline components, viz. p-methoxyphenyl-p''-methoxy benzoate and Schiff base have been studied.One of the eight binary systems involving Schiff base p-tolual-p-phenetidine was found to give monotropi
Doshi, A.V.,Joshi, N.N.
p. 807 - 810
(2007/10/02)
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