Nucleophilic Attack vs. General Base Assisted Hydrolysis in the Reactions of Acetic Anhydride with Primary and Secondary Amines. pH-Yield Studies in the Recognition and Assessment of the Nucleophilic and General Base Reactions

1994 ◽  
Vol 59 (5) ◽  
pp. 1095-1101 ◽  
Author(s):  
James F. King ◽  
Zhen Rong Guo ◽  
Darryl F. Klassen
1986 ◽  
Vol 64 (12) ◽  
pp. 2274-2278 ◽  
Author(s):  
Kenneth T. Leffek ◽  
Urszula Maciejewska

The reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene (1) in acetonitrile solvent gives first 2,2-di(4-nitrophenyl)-1-fluoro-1-aminoethene (2) and then 2,2-di(4-nitrophenyl)-1,1-difluoro-1-aminoethane (3). With excess amine, pseudo-first-order rate constants for the production of 2 were measured, which showed a second-order reaction, together with a catalysed third-order reaction. In addition to the reagent amines, the reaction is also catalysed by tertiary amines and bases such as oxalate and acetate, but not by chloride and perchlorate, nor by ammonium ions. The enthalpy of activation for the reaction of piperidine with 1 in acetonitrile is 3.7 kcalmol−1, but for the catalysed reaction an apparent value of −2.2 kcal mol−1 was obtained. It is concluded that the reaction proceeds via a pre-equilibrium to a zwitterion, followed by another equilibrium giving a carbanion that yields the product (2) by a rate-determining cleavage of the carbon–fluorine bond.


1977 ◽  
Vol 30 (9) ◽  
pp. 2063 ◽  
Author(s):  
DW Cameron ◽  
EL Samuel

π-Deficient perimidin-4- and -6-one systems reacted readily with primary and secondary amines at room temperature. Nucleophilic attack occurred not only at the enone double bond, but also at positions 7 and 9 on the benzenoid ring. Highly coloured mono-, di- or tri-aminated derivatives were thereby obtained. A significant degree of bond fixation was indicated. Side-chain amination of 9-methyl substituents was observed, analogous to processes encountered in quinone chemistry. On continued contact with amine the products were converted partly into 9-formyl derivatives and partly into 9-amino compounds.


1987 ◽  
Vol 52 (11) ◽  
pp. 2699-2709 ◽  
Author(s):  
Dalimil Dvořák ◽  
Zdeněk Arnold

Reaction of arylmethylenemalonaldehydes with tributylphosphine and tertiary amines affords compounds of dipolar structure whereas reaction with primary and secondary amines leads to 1,4-addition products. Salts of nucleophilic inorganic anions add to arylmethylenemalonaldehydes under formation of salts of substituted malonaldehydes.


1984 ◽  
Vol 49 (1) ◽  
pp. 110-121 ◽  
Author(s):  
Jiří Křepelka ◽  
Drahuše Vlčková ◽  
Milan Mělka

Alkylation of derivatives of 4-aryl-1-naphthols (I-V) by 2,3-epoxypropyl chloride in methanolic sodium hydroxide gave epoxy derivatives VI, VIII, IX, XI and XII, apart from products of cleavage of the oxirane ring, VII and X. Analogous alkylation of compounds I, IV and V by 2-(N,N-diethylamino)ethyl chloride hydrochloride in a two-phase medium afforded basic ethers XIII to XV. The cleavage of the oxirane ring in compound VI by the action of primary and secondary amines, piperidine and substituted piperazines led to compounds XVI-XXIV. Reaction of thionyl chloride with compounds XXI, XXII and XXIV gave chloro derivatives XXV-XXVII.Exposure of compound XXII to 4-methylbenzenesulfonyl chloride produced compound XXVIII, retaining the secondary alcoholic group. In an antineoplastic screening in vivo none of the compounds prepared had an appreciable activity. Compound XVII, being an analogue of propranolol, was used in the test of isoproterenolic tachycardia, and showed a beta-lytic effect comparable with that of propranol.


ChemInform ◽  
2014 ◽  
Vol 45 (30) ◽  
pp. no-no
Author(s):  
Dmitry B. Ushakov ◽  
Kerry Gilmore ◽  
Daniel Kopetzki ◽  
D. Tyler McQuade ◽  
Peter H. Seeberger

1983 ◽  
Vol 105 (15) ◽  
pp. 5002-5011 ◽  
Author(s):  
Shunichi Murahashi ◽  
Noriaki Yoshimura ◽  
Tatsuo Tsumiyama ◽  
Takeyuki Kojima

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