Carbylamine reaction isocyanides

Give the isocyanide (carbylamine) reaction, if the anilide is an acylated primary amine. 

Isocyanide (or carbylamine) reaction. Dissolve 1 ml. of chloroform in 2-3 ml. of alcoholic NaOH solution, add a few drops of aniline, mix well and warm gently the foul odour of isocyanide is produced. 

HOFMANN CARBYLAMINE REACTION te ft-BUTYL ISOCYANIDE (2-Methylpropane, 2-isocyano)... 

Various synthetic routes to isocyanides have been reported since their identification over 100 years ago.8 Until now, the useful synthetic procedures all required a dehydration reaction8-11 Although the carbylamine reaction involving the dichlorocarbene intermediate is one of the early methods,8 it had not been preparatively useful until the innovation of phase-transfer catalysis (PTC).4 5... 

Aliphatic and aromatic primary amines on heating with ehloroform and ethanolic potassium hydroxide form isocyanides or earbylamines which are foul smelling substances. Secondary and tertlaiy amines do not show this reaction. This reaction is known as carbylamine reaction or Isocyanlde test and Is used as a test for primary amines. 

This reaction was first reported by Hofmann in 1868. It is the synthesis of isonitriles (also known as isocyanides) from primary amines and chloroform in the presence of alkali and is known as the Hofmann isonitrile synthesis, Hofmann carbylamine reaction, or Hofmann carbylamine synthesis. This reaction has been used to test the presence of primary amines from the order of isocyanides. Alternatively, the isonitriles can be prepared by means of the treatment of formamide of primary amines with toluenesulfonyl chloride" or phosphorus oxychloride (POCls)." Currently, the isonitriles have gained much attention in organic synthesis because of their application as versatile building blocks for heterocycles and in multicomponent reactions to generate combinatorial libraries, such as that in the Passerini reaction and Ugi reaction ... 

The isocyanide RNC is recognized by its unpleasant smell. This reaction of primary amines is called the carbylamine reaction. 

Dibromocarbene has been utilized in place of dichlorocarbene in the phase transfer Hofmann carbylamine reaction (see Sect. 3.5). Methyl and ethyl isocyanide are low boiling and separation of these products from residual chloroform is difficult. The purification can be facilitated by use of bromoform in these two cases (Eq. 4.8) [16]. 

Phenyl Isocyanide In 1972, Ugi and coworkers first synthesized phenyl isocyanide (PhIC) (11) via the Hoffmann carbylamine reaction [51]. Mjalli and coworkers [50] have also synthesized it following a procedure reported by Wal-borsky and Ronman [52] (Scheme 7.30). It can be purified by distillation to obtain a light yellow oil, which has a boiling point of 53°C. 

Isocyanides (isonitriles or carbylamines) are formed in this reaction. 

The realization that this was a new type of compound, isomeric to the nitriles, and the elaboration of the classical methods for the preparation of isocyanides, the alkylation method and the carbylamine method by Gautier and Hofmann, initiated an active period of isocyanide chemistry that ended by the turn of the century with Nef s investigations on the reactions of the formally divalent carbon atom in the isocyanides. - TTie discovery of the Passerini reaction in 1921 led to a brief renaissance of isocyanide chemistry. 

When an alkyl halide is treated with silver cyanide, reaction takes place in the usual way a silver halide and an organic compound are formed. The product, however, is not an alkyl cyanide, as is the case when potassium cyanide is used, but an isomeric compound. The substances prepared from silver cyanide are called isocyanides, isonitriles, or carbylamines. The last name is given to them on account of the fact that they unite with acids and thus resemble the amines. The addition-products do not, however, resemble salts in their chemical properties. When hydrogen chloride is passed into an ethereal solution of methyl isocyanide, a compound of the formula 2CH3NC.3HCI is formed, which is decomposed when brought into contact with water. 

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