954-21-2Relevant academic research and scientific papers
Direct synthesis of amides from nonactivated carboxylic acids using urea as nitrogen source and Mg(NO3)2or imidazole as catalysts
Blacker, A. John,Chhatwal, A. Rosie,Lomax, Helen V.,Marcé, Patricia,Williams, Jonathan M. J.
, p. 5808 - 5818 (2020/06/21)
A new method for the direct synthesis of primary and secondary amides from carboxylic acids is described using Mg(NO3)2·6H2O or imidazole as a low-cost and readily available catalyst, and urea as a stable, and easy to manipulate nitrogen source. This methodology is particularly useful for the direct synthesis of primary and methyl amides avoiding the use of ammonia and methylamine gas which can be tedious to manipulate. Furthermore, the transformation does not require the employment of coupling or activating agents which are commonly required.
Synthesis of α-amino amides via N,O-acetals derived from Weinreb amides
Hirner, Sebastian,Somfai, Peter
supporting information; experimental part, p. 7798 - 7803 (2009/12/29)
(Chemical Equation Presented) An easy and straightforward synthesis of α-amino amides via a base-mediated rearrangement of modified Weinreb amides into N,O-acetals is presented. Subsequent arylation, alkylation, alkenylation, or alkynylation of this intermediate affords the corresponding R-amino amides in excellent yields. Furthermore, a more generalized protocol for the α-arylation of Weinreb amides lacking an R-amino moiety is also discussed.
Study of the reactivity of α-acylenaminoketones. Synthesis of pyrazoles
Negri,Kascheres
, p. 109 - 123 (2007/10/03)
The reactions of 4-(methylamino)-3-penten-2-one with diazoketones yielded the α-acylenaminoketones 1-3 in good yields. Preparation of the α-acylenaminoketone 4 was carried out by treatment of 4-(t-butylamino)-3-penten-2-one with benzoyl chloride being followed by reaction of transamination with methylamine. The reactions were carried out in five different solvents and were submitted to gas chromatography/mass spectrometry analysis, with the goal of obtaining substituted pyrazoles and determining which of the carbonyls would preferentially be attacked by the nucleophile. The reactions of compounds 1-4 with hydrazine reagents led to the formation of the pyrazoles 5-7a-q. Small amounts of 4-methylamino-2-pentenones 10a-q, amides 11a-q and pyrazoles 12a-q were also obtained in these reactions. The unexpected formation of pyrazoles 15d,h,q was detected when methanol and N,N-dimethylformamide were used as solvents in the reactions of α-acylenaminoketone 4 with hydrazine reagents.
Principal Component Analysis on the effect of nucleophiles on the reactivity of α-acylenaminoketones
Kascheres, Concetta,Negri, Giuseppina,Ferreira, Marcia M.C.,Sabino, Luciana C.
, p. 2237 - 2243 (2007/10/03)
This report shows the importance of Principal Component Analysis for grouping types of products observed when α-acylenaminoketones K1-K3 react with four substituted hydrazine nucleophiles in five organic solvents. The reactions were carried out with the g
Some Unusual Reaction of Weinreb Amides
Keck, Gary E.,McHardy, Stanton F.,Murry, Jerry A.
, p. 6215 - 6218 (2007/10/02)
Certain N-methoxy-N-methyl amides yield products of formal reduction and/or rearrangement upon exposure to tert-butyldimethylsilyl triflate and collidine or triethylamine.
Experimental and Theoretical Study of the Reactivity of Primary and Secondary Enaminones toward Diphenylketene. A Comparison of AM1 and HAM/3 Semiempirical Methods
Eberlin, Marcos N.,Takahata, Yuji,Kascheres, Concetta
, p. 5150 - 5155 (2007/10/02)
Diazodiphenylethanone (1) reacts with acyclic enamino ketones 2 and enamino esters 3 to form products of electrophilic attack of diphenylketene at Cα (5) and nitrogen (6 and 7).The relative reactivity of the different enaminones was shown to be consistent with HOMO energies determined by the HAM/3 semiempirical method.However, this approach could not completely explain the reactivity of the cyclic enamino ketones 4, which, by HAM/3, show a high energy second HOMO corresponding to the nonbonded pair of electrons on oxygen.
MESOIONIC TRIAZOLE BY REACTION OF A SUBSTITUTED 4,4-DICHLORO β-LACTAM WITH PHENYLHYDRAZINE
Clef, B. Le,Vermylen, L.,Viehe, H. G.,Meerssche, M. Van,Germain, G.,Declercq, J. P.
, p. 1035 - 1036 (2007/10/02)
β-Lactam 1 undergoes substitution of its chlorine atoms in the presence of methanol but suprisingly produces the triazole 4 upon reaction with phenylhydrazine.
