Nitration anilides

Samal et al. [25] reported that Ce(IV) ion coupled with an amide, such as thioacetamide, succinamide, acetamide, and formamide, could initiate acrylonitrile (AN) polymerization in aqueous solution. Feng et al. [3] for the first time thoroughly investigated the structural effect of amide on AAM polymerization using Ce(IV) ion, ceric ammonium nitrate (CAN) as an initiator. They found that only acetanilide (AA) and formanilide (FA) promote the polymerization and remarkably enhance Rp. The others such as formamide, N,N-dimethylformamide (DMF), N-butylacetamide, and N-cyclohexylacetamide only slightly affect the rate of polymerization. This can be shown by the relative rate (/ r), i.e., the rate of AAM polymerization initiated with ceric ion-amide divided by the rate of polymerization initiated with ceric ion alone. Rr for CAN-anilide system is approximately 2.5, and the others range from 1.04-1.11. 

Siddall and his co-workers (46) have examined the barriers to rotation of a series of 2,6-disubstituted anilides. Af-Ethyl-A/-(2,6-xylyl)formamide (9) was recrystallized as a uranyl nitrate complex, and one isomer, which at equilibrium was favored by a factor of 3 1, was enriched up to a 30 1 ratio. The kinetics of rotation were examined at 0 to 29°C. The Arrhenius activation energy was 26 3 kcal/mol and log A was 18.5 2.4 hr-1. Siddall and Gamer (47) were able to obtain an almost pure isomer (which also predominated at equilibrium 1.3 1 for the ethyl compound and 1.1 1 for the methyl compound) of Ar-alkyl- V-(2-methyl-4,6-dibromophenyl)-l-naphthamide (10). The half-lives of... 

Nitrations of phenyl derivatives of small ring heterocycles have been little studied. The nitration of 3-(4-nitrophenyI)-l-phenyl-2,2-dichloroaziri-dine (90) using potassium nitrate in sulfuric and acetic acids yields 1,3-bis(4-nitrophenyl)-2,2-dichloroaziridine and 3-(4-nitrophenyl)-l-(2-nitro-phenyl)-2,2-dichloroaziridine in 65 35 ratio. Under the same conditions the diphenyl derivative undergoes cleavage of the aziridine ring to give a mixture of nitrated anilides. 

K. Lauer [62] obtained the results (given in Table 5) by nitrating aniline and anilides with nitric and with mixtures of nitric and sulphuric or acetic acids at 20°C, over 24 hr. 

Nitration also takes place directly with the anilides (acetanilide or benzanilide), which may then be hydrolyzed yielding nitro aniline. In this case the para compound is obtained almost exclusively. 

The ortho para ratio is also influenced by the nitration medium in a manner which cannot be explained by the Robinson-Ingold theory. The isomer distribution which results from the nitration of aniline and anilides in several nitrating media is shown in Table 4-6. 

Table 4-6. Nitbation of Aniune and Anilides Continued) Nitration with 94 Per Cent HNO3 in Concentrated HsS04...

Its nitrogen readily becomes pentavalent, forming quaternary ammonium salts. Some derivatives of known properties, useful for qualitative identification are the hydrochloride, white crystals melting at 272° with decomposition the nitrate, m.p. 184-185° the picrate, yellow rhombic prisms (from absolute alcohol) melting at 221-222° to a red oiB the />-toluidine, m.p. 150° and the anilide , m.p. 85°. Alkyl iodides readily react with it to form water-soluble compounds. The carboxylic group of nicotinic acid behaves typically, forming salts with alkalies, alkaline earth hydroxides or heavy metals the latter salts are quite insoluble and their preparation is useful to separate nicotinic acid from mixtures. 

In comparison with alkyl halogenides, halides bound to aromatic nuclei are less reactive, and, unless activated by the presence of other substituents (for example, reactive chlorine in 2,4-dinitrochlorobenzene), nucleophilic substitution reactions cannot be used for their identification. For the identification, electrophilic substitution reactions on aromatic nuclei are used predominantly, such as nitration and chlorosulfonation. Only in exceptional and special cases are other procedmes used [preparation of Grignard reagent and the conversion to anilides (12) preparation of addition compounds with picric acid-chloronaphthalenes, see p. 127 oxidation of side chains-oxidation of chlorotoluene to the corresponding chlorobenzoic acid, see p. 129]. 

Sana et al. (2012) have carried out solvent-free and microwave-assisted nitration reactions, which underwent smoothly in the presence of group V and VI metal salts with high regio-selectivity for anilides, moderately and nonactivated aromatic compounds. Good to excellent yields were obtained under solvent-free conditions and the nitration was completed in few minutes under microwave irradiation. It was observed that when the ortho position was engaged, p-nitro derivatives were obtained, while o-nitro derivatives were obtained when para position was engaged. The nitration of aromatic carbonyl and related compounds was observed with good yield and the reaction times were about 3-5 min. 

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