Acetanilides halogenation

Scheme 11.2 shows some representative halogenation reactions. Entries 1 and 2 involve Lewis acid-catalyzed chlorination. Entry 3 is an acid-catalyzed chlorination using NCS as the reagent. Entry 4 shows a high-yield chlorination of acetanilide by i-butyl hypochlorite. This seems to be an especially facile reaction, since anisole is not chlorinated under these conditions, and may involve the A-chloroamide as an intermediate. Entry 5 describes a large-scale chlorination done with NCS. The product was used for the synthesis of sulamserod, a drug candidate. 

Tellurium Tetrahydrofuran Tetranitroaniline Tetranitromethane Thiocyanates Thionyl chloride Thiophene Thymol Halogens, metals Tetrahydridoaluminates, KOH, NaOH Reducing materials Aluminum, cotton, aromatic nitro compounds, hydrocarbons, cotton, toluene Chlorates, nitric acid, peroxides Ammonia, dimethylsulfoxide, linseed oil, quinoline, sodium Nitric acid Acetanilide, antipyrine, camphor, chlorohydrate, menthol, quinine sulfate, ure- thene... 

Elemental Analysis. The acetone fractions were analyzed for C, H,- and N by an automatic analyzer. Sulfur and the halogens (i.e., Cl and Br) were analyzed by combustion and subsequent titration. The following standard compounds were used for quality assurance (QA) purposes acetanilide (C, H, N), sulfanilamide (S), p-chlorobenzoic acid (Cl), and p-bromobenzoic acid (Br). 

Ethyl ethylenetetracarboxylate has been prepared from monochloro- and monobromomalonic ester through removal of halogen acid with sodium,1 sodium ethylate,2 potassium acetate,3 potassium carbonate,4 sodium urethane, sodium formanilide and sodium acetanilide.6 It has also been prepared by treating the disodium derivative of ethyl ethane-1,1,2,2-tetracarboxylate with bromine,7 or iodine 8 by treating dibromomalonic ester with sodium,9 or sodium ethylate 10 and by treating the disodium derivative of malonic ester with iodine.11... 

Fc = semi empirical polarity correction factor derived for several classes of compounds (i.e., acetanilides = 0.31 amides = 0.66 halogenated aromatic hydrocarbons = -0.20 non-halogenated aromatic hydrocarbons = -0.27 carbamates = 0.27 dinitroanilines = 0.19 organophosphorous pesticides = 0.01 PAHs = -0.93, triazines = 0.24, triazoles = -0.22 ureas = 0.19). 

Preparation of diazoketones and their rearrangements during hydrolysis (method 271) and alcoholysis (method 295) are discussed elsewhere. Ammonolysis of diazoketones leads to amides of acids containing one more carbon atom than the original acyl halide. Halogen atoms may be present in a remote position on an aliphatic chain. The reaction is carried out by heating the diazoketone in alcohol or dioxane solution with aqueous ammonia in the presence of silver oxide or silver nitrate catalysts. Substituted acetanilides are formed when aniline is used in place of ammonia. ... 

The direct chlorination or bromination of aniline takes place more easily than that of benzene, the result being the symmetrical tri-chlor or tri-brom aniline, viz., i-amino 2-4-6-tri-chlor benzene, C6H2CI3-(NH2) and I-amino 2-4-6-tri-brom benzene, CeH2Br3(NH2). The mono-halogen anilines are prepared by reducing mono-chlor nitro benzenes, or by halogenating acetanilide and then hydrolyzing. 

Chemical/Pharmaceutical/Other Class Halogen-ated hydrocarbon pesticide. Specifically, a chloro-acetanilide herbicide Chemical Formula C11H14CINO... 

Metazachlor (21) is a halogenated acetanilide developed by the BASF, with the chemical name 2-chloro-2,6-dimethyl-N-(lH-pyrazol-l-yl-methyl)acetanilide (Stormonth and Woodroffe, 1982). 

Aniline, acetanilide, benzyl alcohol or methyl benzoate containing a halogen atom in the or /zo-position react with 1 -alkynes in the presence of bis(triphenylphosphine)palladium(II) chloride and copper(I) iodide to give the corresponding o-alkynylbenzenes (e.g. equation 6). Some of the products can be cyclized the aniline derivative 53, for instance, is converted into 2-phenylindole in 99% yield on treatment with a catalytic amount of copper(I) iodide. ... 

Purpose. This experiment extends our understanding of the experimental conditions under which electrophilic aromatic substitution reactions are carried out (also see Experiments [27] and [29A]-[29D]). It deals with electrophilic aromatic halogenation. The directive influence of the acetamido, —NHCOCH3, group on the bromination of acetanilide is explored. 

Ar. halogenation of overactive substrates such as acetanilides has been performed smoothly by using TiCl in the presence of an oxidant . Very reactive heterocyclics have been brominated with 2,4,4,6-tetra-bromo-2,5-cyclohexadienone . 

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