Reaction CVI.—Action of Acyl Chlorides on Alcohols

With aromatic acyl chlorides the reaction is not so rapid, but it can be greatly facilitated by the presence of caustic soda or caustic potash in dilute aqueous solution (Schotten-Baumann). 

The Schotten-Baumann reaction can also be applied to primary and secondary aromatic amines (see p. 303) it is much used in the identification of compounds to which it can be applied, by the preparation of their benzoyl, phenylacetyl, or benzene sulphonyl derivatives. 

Preparation 208.—Ethyl Acetate [Ethyl ester of ethan add]. 

To 10 gms. (excess) of absolute alcohol, 15 gms. (1 mol.) of acetyl chloride (see p. 332) are added drop by drop with good cooling and shaking, the temperature not being allowed to rise above 20°. The whole is carefully diluted with an equal volume of saturated brine, and the ethyl acetate which floats on the surface separated, well washed with a 50% solu- 

of 3 5-dinitrobenzoic acid and 5 gms. of phosphorus penta-chloride are gently warmed and the mixture allowed to cool. The solid dinitrobenzoyl chloride is separated from the phosphorus oxychloride by pressing on a porous plate. The crude chloride is then treated with 5 c.cs. of ethyl alcohol, under reflux, and warmed to about 80° for 10 minutes. The product is crystallised from 60% alcohol. M.P. 92°. (A., 202, 223.) 

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