Benzanilide

Hydrolysis of benzanilide. Place 5 g. of benzanilide and 50 ml. of 70 per cent, sulphuric acid in a small flask fitted with a reflux condenser, and boU gently for 30 minutes. Some of the benzoio acid will vapourise in the steam and solidify in the condenser. Pour 60 ml. of hot water down the condenser this will dislodge and partially dissolve the benzoic acid. Cool the flask in ice water filter off the benzoic acid (anifine sulphate does not separate at this dilution), wash well with water, drain, dry upon filter paper, and identify by m.p. (121°) and other tests. Render the filtrate alkaline by cautiously adding 10 per cent, sodium hydroxide solution, cool and isolate the aniline by ether extraction. Recover the ether and test the residue for anifine (Section IV,100). 

Benzoyl p-toluidide. Use 3-3 g. of p-toluidine, 25 ml. of 10 per cent, sodium hydroxide solution and 4-2 g. (3-5 ml.) of benzoyl chloride. Proceed as above. The yield of benzoyl p-toluidide, m.p. 158°, is 4-5 g. 

J cent, sulphuric acid in a small flask fitted with a reflux condenser, and boU 

I gently for 30 minutes. Some of the benzoic acid will vapourise in the steam 

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Hydrolysis of Acetanilide. Anilides in general, such as acetanilide and benzanilide (p. 245), may be hydrolysed by caustic alkalis or by acids. Alkaline hydrolysis, however, is usually very slow, and therefore... 

Benzanilide (Benzoyl-aniline). CeHeNHCOCeHs (Semi-ndcro Scale.)... 

Hydrolysis of Benzanilide. For this hydrolysis, it is necessary to use 70% sulphuric acid (see Hydrolysis of Acetanilide, p. 108). Add I g. of benzanilide to 10 ml. of 70% sulphuric acid, and boil the mixture gently in a small flask under a reflux water-condenser for 30 minutes. Hydrolysis will now be complete, but much of the benzoic acid will have vaporised in the steam and then solidified in the conden-... 

Acetanilide, benzanilide and their nuclear- and N-substituted derivatives. 

Substances suitable for the estimation acetanilide, diphenylamine, glycine, benzanilide. 

By treatment of this oxime with phosphorus pentachloride or thionyl fhloride in ether solution, smooth conversion into benzanilide, m.p. 163°, results. The change of any oxime into a substituted amide under the conditions mentioned is usually termed the Beckmann rearrangement. The above example may be represented ... 

Beckmann rearrangement of benzophenone oxime to benz-anilide. Dissolve 2 g. of benzophenone oxime in 20 ml. of anhydrous ether in a small conical flask and add 3 g. of powdered phosphorus pentachloride (or 3 ml. of pure tbionyl chloride). Distil off the solvent and other volatile products on a water bath CAUTION ether), add 25 ml. of water, boil for several minutes and break up any lumps which may be formed. Decant the supernatant liquid, and recrystallise, in the same vessel, from boiling alcohol. The product is benzanilide, m.p. 163° confirm this by a mixed m.p. determination with an authentic specimen. 

Benzanilide and similar compounds are very slowly hydrolysed by concentrated hydrochloric acid hydrolysis is quite rapid with 60-70 per cent, sulphuric acid (for experimental details, see Section IV,52). In the preliminary experiment boil 0 5-1 Og. of the compound with 10-20 ml. of dilute sulphuric acid (1 1 by volume) imder reflux for 20-30 minutes. Dilute with 10ml.of water and filteroflfanyacid which may be precipitated if the carboxyhc acid is hquid and volatile, distil it directly from the reaction mixture. Render the residue alkaline and isolate the base as above. 

B. With 70 per cent, sulphuric acid. Reflux 1 g. of the substance (e.g., benzanilide) with 10-15 ml. of 70 per cent, sulphuric acid (4 3 by volume) for 30 minutes. Allow to cool and wash down any acid which has sublimed into the condenser with hot water. Filter off the acid, wash it with water, and examine for solubility, etc. Render the filtrate alkaline... 

Benzanilide [93-98-1] M 197.2, m 164", pK 1.26. Crystd from pet ether (b 70-90°) using a Soxhlet extractor, and dried overnight at 120°. Also crystd from EtOH. 

Reaction of benzanilide (CgHjNHCCgHj) with chlorine in acetic acid yields a mixture of two monochloro derivatives formed by electrophilic aromatic substitution. Suggest reasonable structures for these two isomers. 

Benzoyl Chloride.—The formation of esters by ibe action of benzoyl chloride or othei acid chloride on an alcohol or ]ohcnol in presence of caustic soda is known as the Schotten- 13riumann reaction. The reaction may also be employed in the preparation of deri ati es of the aromatic amines containing i.n acid radical, like benzanilide, CjjH NH.CO... 

The ring contraction of 3//-azepines is also promoted by acylating agents,54 35 and by arenesulfonyl halides.34 For example, in refluxing acetic anhydride A,-phenyl-3//-azepin-2-amine yields 2-acetamidodiphenylamine (22% mp 121-122°C),34 whereas A,A,-diethyl-3/7-azepin-2-amine (30) with 4-nitrobenzoyl chloride in pyridine yields the benzanilide 31.35... 

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