CARBYLAMINE REACTION

Reimer Tiemann Reaction||Abnormal Reimer Tiemann Reaction||Kolbe Schmidt Reaction|| HOFmannIsocyanide Reaction (Carbylamine Test)

It is believed that chloroform and hydroxide ion react to produce an electron deficient intermediate dichlorocarbene : C Cl_(2) (DC C) Treatment of phenol with DCC in basic medium introduces an aldehyde group, onto the aromatic ring. This reaction is known as Reimer Tiemann reaction. The Reimer-Tiemann reaction involves electrophilic substitution on highly reactive phenoxide ring The electrophilic reagent is dichloro carbene : C Cl_(2) . o-product is major product because : (i) There are two o-positions available as compared to one para. (ii) o-product is more stable due to the formation ofsix membered chelate formation. If 1^(@) amines (aliphatic and aromatic) react with DCC in basic medium it yield isocyanide or carbylamine. The reaction is known as carbylamine reaction. The product is known as isocyanide & it is a foul smelling substance. Step marked by * is :

Statement 1: Amines are less basic than alcohols. Statement-2: Secondary amines give carbylamine reactions. Statement-3: in Hofmann-bromide reaction amide is converted to amines with same number of carbon atom.

Carbylamine test is given by