Acid nitriles from sulphonic acids

Nitriles from Sulphonic Acids or Aiyl Halides.—Individual acid nitriles will be mentioned at various times whenever they are used in preparing various acids. Several reactions may be employed to prepare the nitriles in which the cyanogen group is in the ring. The simplest method is from sulphonic acids by heating with potassium cyanide. 

Th synthesis of the acid from the nitrile thus becomes in reality a synthesis from sulphonic acids. An exactly analogous reaction takes place when an aryl halide, with the halogen in the side chain, is distilled with potassium cyanide, as discussed later (p. 678). 

The most important reaction of the sulphonic acids is their conversion into phenols by fusion with caustic alkalis. When they are fused with potassium cyanide, nitriles are obtained, e.g. benzonitriie from ben-zenesulphonic acid. 

Aromatic nitriles (or aryl cyanides) can be obtained by methods (1) and (3). but not by method (2). In addition, aromatic nitriles can be prepared by two other methods, (a) from the corresponding diazo compound by Sandmeyer s Reaction (p. 189), (b) by fusing the corresponding sulphonic acid (or its salts)... 

Victor Merz (Odessa, 12 December 1839-Ziirich, 25 May 1904) was associate professor (1869) and professor (1871) in the university of Zurich. He worked first on inorganic chemistry. He synthesised ketones from acid chlorides and hydrocarbons, sodium formate from carbon monoxide, and oxalic acid by heating alkali formates. He prepared aromatic carboxylic acids by distilling sulphonates with potassium cyanide and hydrolysing the nitriles produced, discovered a- and j8-naphthoic acids, and prepared j8-naphthyl-amine from j8-naphthol by the action of ammonia and zinc chloride. ... 

Further examples of the Ritter reaction(cf. section IV.B) are provided by the many substituted olefins that may be protonated to ve carbonium ions which can be intercepted by hydrogen cyanide or organic nitriles cyanogen chloride can also be used as intercepting species , but offers no advantages. Mixtures of the two possible amides, and hence amines, are to be expected from non-terminal alkenes and from such olefinic compounds as oleic acid Olefins may also be converted to amines with yields of up to 60%, by hydroboration and subsequent reaction of the organoborane with chloroamine in alkaline solution or preferably with hydroxylamine-0-sulphonic acid in diglyme (reaction 86) The reaction is applicable... 

Although a few methods for the direct conversion of acids into nitriles are kno vn, the most popular still proceed via dehydration of the corresponding amides. A new, mild, one-pot method to effect the acid-to-nitrile conversion in high yield involves the use of mixed sulphonic-carboxylic anhydrides (Scheme 23) the method, however, is not applicable to acids containing —NHa, — NHR, —OH, or —SH groups. In a similar vein, a new and efficient one-pot synthesis of nitriles from acid chlorides is mediated by sulphonamide at 120 °C. ... 

As might be expected from the strong acidic properties of the solvents protonation occurs with alcohols, ethers s, 46 nitrocompounds, sulphones, alkyl sulphides, nitriles as well as with 7r-bonded systems32 ... 

---