579-11-3Relevant articles and documents
Preparation method of N-chloroacetanilide
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Paragraph 0020-0043, (2019/03/24)
The invention relates to the technical field of veterinary medicine, in particular to a preparation method of N-chloroacetanilide for a synthesis process of doxycycline. The method comprises the following steps: (1) adding reaction solvent water, maintain
Method for synthesizing 4-chloro-2-(trifluoroacetyl)aniline hydrochloride hydrate
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Paragraph 0044; 0045; 0046, (2017/08/28)
The invention relates to a method for synthesizing an efavirenz intermediate, in particular to a method for synthesizing a 4-chloro-2-(trifluoroacetyl)aniline hydrochloride hydrate. The method includes the following steps that an acylating agent is added to aniline in an organic solvent, aniline is subjected to an acylation reaction under the alkaline condition and at the temperature of 5-15 DEG C to obtain a compound A, the compound A reacts with a chlorinating agent under the alkalescent condition to obtain a compound B, the compound B reacts with trifluoroacetic acid ethyl ester under the action of butyl lithium to obtain a compound C, the compound C and hydrochloric acid are subjected to a reflux reaction at 60-65 DEG C, and the 4-chloro-2-(trifluoroacetyl)aniline hydrochloride hydrate is obtained. Reaction conditions are mild, energy consumption is greatly reduced, raw materials in use are easy to obtain, cost is low, and pollution is little. The method is easy to operate, the total yield can reach 77.2%, the purity can reach 99% or above, product quality is good, and the method is suitable for industrial production.
Photoinduced rearrangement of aromatic N-chloroamides to chloroaromatic amides in the solid state: Inverted Πn-ΣN occupational stability of amidyl radicals
Naumov, Pan?e,Topcu, Yildiray,Eckert-Maksi?, Mirjana,Glasovac, Zoran,Pavo?evi?, Fabijan,Kochunnoonny, Manoj,Hara, Hideyuki
scheme or table, p. 7834 - 7848 (2011/08/09)
We report a solid-state photochemical rearrangement reaction by which aromatic N-chloroamides exposed to UV light or sunlight are rapidly and efficiently converted to chloroaromatic amides. The course, the intermediate (nascent chlorine vs dichlorine) and the outcome of the reaction depend on the excitation (exposure time, wavelength, and intensity) and on inherent structural factors (the directing role of the substituents and, as demonstrated by the different reactivity of two polymorphs of N-chlorobenzanilide, the supramolecular structure). The photolysis of the chloroamides provides facile photochemical access to arylamidyl radicals as intermediates, which in the absence of strong hydrogen bond donors are stabilized in the reactant crystals by C-H/N-Cl?π interactions, thus, providing insight into their structure and chemistry. Thorough theoretical modeling of the factors determinant to the stability and the nature of the spin-hosting orbital evidenced that although the trans-Π|| state (Np spin) of the amidyls is normally preferred over the trans-Σ⊥ configuration (Nsp2 spin), stabilization by aromatic conjugation, steric and geometry factors, as well as by electronic effects from the substituents can decrease the Π-Σ gap in these intermediates significantly, resulting in similar and, in the case of the orthogonal amide-phenyl disposition, even reversed population of the unpaired electron in the two orbitals. Quantitative correlation established that the inverted occupational spin stability and the ΠN-ΣN crossover are collectively facilitated by the conformation, valence angle, and disposition of the amide group relative to the aromatic system. The stabilization and detection of a trans-Σ⊥ radical was experimentally accomplished by steric locking of the orthogonal trans-amide conformation with double ortho-tert-butyl substitution at the phenyl ring. The effects of the single para-phenyl substituents on the relative occupational stability of the arylamidyl radical states point out to non-Hammett behavior. By including cumulative electronic effects from multiple substitutions, four distinct families of the aromatic amidyl radicals were identified. The Π∥ state is the most stable structure of the N-phenylacetamidyl radical and of most of the substituted arylamidyls, although the Σ⊥ and Π⊥ states can also be stabilized by introducing tert-butyl and nitro groups, respectively.
Nucleophilic Substitution at Centers Other than Carbon: Reaction at the Chlorine of N-Chloroacetanilides with Triethylamine as the Nucleophile
Underwood, Graham R.,Dietze, Paul E.
, p. 5225 - 5229 (2007/10/02)
The reaction between triethylamine (TEA) and a series of para-substituted N-chloroacetanilides has been studied in aqueous solution buffered to pHs between 1 and 5.In these reactions, the exclusive product derived from the aromatic moiety is the corresponding acetanilide.The reaction occurs via two parallel pseudo-second-order paths, one acid catalyzed (the Orton-like mechanism), the other uncatalyzed.The uncatalyzed reaction is accelerated by the presence of electron-withdrawing substituents on the aromatic ring and can best be represented as nucleophilic displacement at chlorine.It therefore appears to be the prototype of a convenient class of reactions for the study of displacement reactions at chlorine.The ρ value for this reaction is 3.87 indicating substantial negative charge buildup in the aromatic ring during the transition state.The acid-catalyzed reaction is more complex, presumably involving a protonation equilibrium for the N-chloroacetanilide prior to the rate-determining step similar to that in the Orton reaction.
