Carbylamine

Isocyanide reaction. Add a few drops of chloroform to about 0 2 g. of the substance, and then 2 3 ml. of ethanolic NaOH solution. Mix well and warm gently the foul odour of isocyanide (carbylamine) is produced. Immediately the odour of isocyanide is detected, cool the tube and add carefully an excess of cone. HCl the isocyanide is thus hydrolysed to the odourless amine. 

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

The carbylamine or taocyanide test for primary amines Section IV,100,(i) is so extremely delicate that it will detect traces of primary amines in secondary and tertiary amines it must therefore be applied with due regard to this factor. 

Carbutamide [339-43-5] Carbylamines Carbyne Carbynes Carcinogenicity Carcinogens... 

Insertions into tertiary C—H bonds can be carried out with moderate yields. Among other less common reactions improved by the use of PTC-generated CCI2 are the carbylamine synthesis (RNH2 — R NC) (33). Alkylidene carbene (R2C=C ) and alkenyUdene carbene (R2C=C=C ) adducts have also been prepared (34,35). 

Chloroform reacts with aniline and other aromatic and aliphatic primary amines in alcohoHc alkaline solution to form isonitnles, ie, isocyanides, carbylamines, as shown ... 

Phenyhsonitrile has a powerful characteristic odor it is used as a qualitative test (the carbylamine test) for chloroform or primary aromatic amines. Chloroform reacts with phenols in alkaline solution to give hydroxyaromatic aldehydes in the Reimer-Tiemann reaction eg, phenol gives chiefly Nhydroxyben2aldehyde and some sahcylaldehyde (11) (see Hydroxybenzaldehydes). 

In the known absence of bromoform, iodoform, chloral, and other halogenated methanes, the formation of phenyhsonitrile with aniline provides a simple and faidy sensitive but nonspecific test for the presence of chloroform, the carbylamine test. Phenyhsonitrile formation is the identification test given in the British Pharmacopoeia. A small quantity of resorcinol and caustic soda solution (10% concentration) added to chloroform results in the appearance of a yellowish red color, fluorescing yeUow-green. When 0.5 mL of a 5% thymol solution is boiled with a drop of chloroform and a small quantity of potassium hydroxide solution, a yellow color with a reddish sheen develops the addition of sulfuric acid causes a change to brilliant violet, which, diluted with water, finally changes to blue (33). 

The common impurities found in amines are nitro compounds (if prepared by reduction), the corresponding halides (if prepared from them) and the corresponding carbamate salts. Amines are dissolved in aqueous acid, the pH of the solution being at least three units below the pKg value of the base to ensure almost complete formation of the cation. They are extracted with diethyl ether to remove neutral impurities and to decompose the carbamate salts. The solution is then made strongly alkaline and the amines that separate are extracted into a suitable solvent (ether or toluene) or steam distilled. The latter process removes coloured impurities. Note that chloroform cannot be used as a solvent for primary amines because, in the presence of alkali, poisonous carbylamines (isocyanides) are formed. However, chloroform is a useful solvent for the extraction of heterocyclic bases. In this case it has the added advantage that while the extract is being freed from the chloroform most of the moisture is removed with the solvent. 

Steam distd (to remove small quantities of carbylamine). The distillate was extracted into ether, washed with dil Na2C03, dried overnight with CaCXj, and the ether removed by evaporation. The residue was distd at 40mm (b 96°) [Kice, Perham and Simons J Am Chem Soc 82 834 I960],... 

The idea that dichlorocarbene is an intermediate in the basic hydrolysis of chloroform is now one hundred years old. It was first suggested by Geuther in 1862 to explain the formation of carbon monoxide, in addition to formate ions, in the reaction of chloroform (and similarly, bromoform) with alkali. At the end of the last century Nef interpreted several well-known reactions involving chloroform and a base in terms of the intermediate formation of dichlorocarbene. These reactions included the ring expansion of pyrroles to pyridines and of indoles to quinolines, as well as the Hofmann carbylamine test for primary amines and the Reimer-Tiemann formylation of phenols. 

ISONITRILES. This designation includes isocyanides (see Vol 3, C582-L to C583-L and Vol 7, I135-R for Cyanicic Acid and-Derivatives) and Carbylamines, R.NiC. The first isonitriles were prepd in 1886 by Gautier, by the action of Ag cyanide on alkyl iodides. Later, Hofmann prepd them by the action of chlf ale KOH on primary amines ... 

The versatility of this method for the alkylation of compounds containing active methylene groups is illustrated by Table I. Review articles have recently appeared,34 and the application to the Hofmann carbylamine reaction is described in the following procedure in this volume, p. 96. 

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... 

Carboxylic acids, a-bromination of 55, 31 CARBOXYLIC ACID CHLORIDES, ketones from, 55, 122 CARBYLAMINE REACTION, 55, 96 Ceric ammonium nitrate [Ammonium hexa mtrocerate(IV)[, 55, 43 Chlorine, 55, 33, 35, 63 CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Cinnamomtnle, a-phenyl- [2-Propeneni-tnle 2,3-diphenyl-], 55, 92 Copper(l) iodide, 55, 105, 123, 124 Copper thiophenoxide [Benzenethiol, copper(I) salt], 55, 123 CYCLIZATION, free radical, 55, 57 CYCLOBUTADIENE, 55, 43 Cyclobutadieneiron tricarbonyl [Iron, tn-carbonyl(r)4-l,3-cyclo-butadiene)-], 55,43... 

Phenyl Carbylamine Chloride Phenyl Dibromoarsine Phenyl Dichloroarsine Phenyl Mercury Acetate Phenylaceyl Chloride Phenylarsenic Dichloride Phenylarsonous Dichloride Phenylcarbamine Phenylcarbonimidic Dichloride Phenylchloromethylketone Phenylisocyanide Dichloride Phenylisonitrile Dichloride Phenylmethylaminpropane Philippine Downy Mildew Phix... 

Acid catalysed hydrolysis of isocyanides ( carbylamines ) to primary amines and formic acid is very rapid, sometimes explosively so. 

Synonyms AI3-28280 Aliphatic isocyanate BRN 0605318 CCRIS 1385 EINECS 210-866-3 Isocyanatomethane Isocyanic acid, methyl ester Methyl carbonimide Methyl carbylamine Methyl isocyanide MIC Monoisocyanate NSC 64323 RCRA waste number P064 TL 1450 UN 2480. 

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