P-Chloroacetanilide

Hydrolysed by dilute acids and alkalis to aniline. It chlorinates more slowly than aniline to o-and p-chloroacetanilides. 

If either the o- or -position is occupied, only one isomer is obtained transformation to the mefo-position does not occur. This is a standard method of preparation of acyl-amino-ketones, or by a further hydrolysis of amino-ketones. The tendency, illustrated in this reaction, of groups to wander from the amino group to the nucleus, is also shown in previous reactions and in the preparation of aminoazobenzene from diazoamino-benzene (Preparation 456), of sulphanilic acid from aniline sulphate (Preparation 292), of o- and p-chloroacetanilides from acetochloranilide (Preparation 328), of o- and p-toluidine from methylaniline hydrochloride, and of 1 2 4-aminodimethylbenzene (2 4-xylidine) from dimethylaniline hydrochloride. 

The significance of polar axes can be demonstrated, for example, in crystal morphology. A few examples will be mentioned here following Curtin and Paul s review of the chemical consequences of the polar axis in organic crystal chemistry [37], Figure 2-32a shows a centrosymmetric acetanilide crystal. The faces occur in parallel pairs and the crystal is non-polar. On the other hand, the p-chloroacetanilide crystal shown in Figure 2-32b is noncentrosymmetric and some of the... 

Figure 2-32. Two crystals from Groth s Chemische Kristallographie [38], (a) Centrosymmetric rhombic bipyramidal acetanilide (b) Noncentrosymmetric rhombic pyramidal p-chloroacetanilide.

The morphological symmetry differences between the acetanilide and p-chloroacetanilide crystals originate from their internal structures. The acetanilide molecules appear in pairs and the two molecules in each pair are related by an inversion center. On the other hand, the p-chloroacetanilide molecules are all aligned in one direction. The molecular arrangements in the two crystals are shown in Figure 2-33. 

Haloanilines are obtained from halonitrobenzenes preferably by the iron-acid reduction procedure. Nuclear halogenation occurs during the reduction of nitrobenzene by stannous chloride in the presence of acetic anhydride a quantitative yield of p-chloroacetanilide is obtained. Hydrogenation of halonitrobenzenes over Raney nickel catalyst is possible provided that the temperature is kept below 150°, at which point... 

Simultaneous hydrocodone, p-aminophenol, hydromorphone, codeine, p-chloroacetanilide... 

Simultaneous acetaminophen, p-aminophenol, p-chloroacetanilide, hydrocodone, hydro-morphone... 

Chloroacetaldehyde, 225 p-Chloroacetanilide, 164 Chloroacetate, 225 4 -Chloro-4-acetylaminostilbene, 164 Chloroaniline, 135... 

M.p. 91°. Prac. insol. cold HgO. Heat alone or warm with abs. EtOH —> o- and p-chloroacetanilides. 

Hinson JA, Mitehell JR, Jollow DJ (1975) Microsomal N-hydroxylation of p-chloroacetanilide. Mol Pharmacol 11 462-469... 

Fresen [57 a] has hydrolysed with acid, treated the mixture with ammonium hydroxide, extracted the hydrolysis products (phenetidine, p-chloroaniline and possibly aniline) with ether, applied aliquots of the ether extract to a silica gel layer and developed with methylene dichloride. A 3% solution of permanganate in concentrated sulphuric acid was used for detection. Thoma s method [164a] is even more sensitive he carries out acid hydrolysis, renders basic with ammonium hydroxide, dilutes with methanol and applies this solution to the thin layer. The p-chloroaniline and any other amines present are detected by diazotisation and coupling. Down to 10 ppm of p-chloroacetanilide can be detected in this way. 

C8H8BrN30ft, N,3-Dimethyl-4-bromo-2,6-dinitroaniline, 32B, 96 C8H8C1NO, p-Chloroacetanilide, 31B, 70... 

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