Acid chlorides of aliphatic acids

REACTIONS AND CHARACTERISATION OF ACID CHLORIDES OF ALIPHATIC ACIDS... 

Reactions and characterisation of acid chlorides of aliphatic acids. 369... 

Acid chlorides of aliphatic acids, 367 reactions and characterisation of, 369, 1059 table of 371 ... 

Phosphorus trichloride is used in numerous reactions with organic compounds containing hydroxyl to replace this radical by chlorine by this means, for example, the chlorides of aliphatic alcohols, etc. may be obtained. The other product is phosphorous acid. 

If an ortho-substituted benzene ring is attached to the nitrogen, the self-condensation is minimized due to steric hindrance and the yield of imidoyl chlorides increases in this order CH3 < Cl < Br ( ). Likewise, lowering of the basicity of the nitrogen prevents condensation. For example, N-sulfonimidoyl chlorides of aliphatic carboxylic acids are obtained in excellent yield ( ). The carboxylic acid amides of a,j8-unsaturated acids also do not undergo tautomerization, because the formation of allenes is not favored under mild conditions... 

Imidoyl chlorides of aliphatic carboxylic acids To the solution of... 

On acetylation it gives acetanilide. Nitrated with some decomposition to a mixture of 2-and 4-nitroanilines. It is basic and gives water-soluble salts with mineral acids. Heating aniline sulphate at 190 C gives sulphanilic add. When heated with alkyl chlorides or aliphatic alcohols mono- and di-alkyl derivatives are obtained, e.g. dimethylaniline. Treatment with trichloroethylene gives phenylglycine. With glycerol and sulphuric acid (Skraup s reaction) quinoline is obtained, while quinaldine can be prepared by the reaction between aniline, paraldehyde and hydrochloric acid. 

The chlorides of tertiary aliphatic alcohols are readily prepared by the action of concentrated hydrochloric acid upon the alcohol at the laboratory temperature, for example ... 

The conversion of aliphatic acids Into their acid chlorides is usually accomplished with —... 

The above simple experiments illustrate the more important properties of aliphatic acid chlorides. For characterisation, the general procedure is to hydrolyse the acid chloride by warming with dilute alkali solution, neutralise the resulting solution with dilute hydrochloric acid (phenol-phthalein), and evaporate to dryness on a water bath. The mixture of the sodium salt of the acid and sodium chloride thus obtained may be employed for the preparation of solid esters as detailed under Aliphatic Acids, Section 111,85. The anilide or p-toluidide may be prepared directly from the acid chloride (see (iii) above and Section III,85,i). 

The physical properties of a number of aliphatic acid chlorides are collected in Table 111,88. 

The above simple experiments illustrate the more important properties of the anhydrides of aliphatic acids. For their characterisation, the reaction with aniline or p-toluidine is frequently employed. Alternatively, the anhydride may be hydrolysed with dilute alkali as detailed under Acid Chlorides, Section 111,88, and the resulting acid characterised as in Section 111,85. 

The use of aliphatic acid anhydrides in place of acid chlorides offers many advantages these include ... 

Acyl halides are intermediates of the carbonylations of alkenes and organic-halides. Decarbonylation of acyl halides as a reversible process of the carbo-nylation is possible with Pd catalyst. The decarbonylation of aliphatic acid chlorides proceeds with Pd(0) catalyst, such as Pd on carbon or PdC, at around 200 °C[109,753]. The product is a mixture of isomeric internal alkenes. For example, when decanoyl chloride is heated with PdCF at 200 C in a distillation flask, rapid evolution of CO and HCl stops after I h, during which time a mixture of nonene isomers was distilled off in a high yield. The decarbonylation of phenylpropionyl chloride (883) affords styrene (53%). In addition, l,5-diphenyl-l-penten-3-one (884) is obtained as a byproduct (10%). formed by the insertion of styrene into the acyl chloride. Formation of the latter supports the formation of acylpalladium species as an intermediate of the decarbonylation. Decarbonylation of the benzoyl chloride 885 can be carried out in good yields at 360 with Pd on carbon as a catalyst, yielding the aryl chloride 886[754]. 

The epoxidation is generally conducted in two steps (/) the polyol is added to epichlorohydrin in the presence of a Lewis acid catalyst (stannic chloride, boron triduoride) to produce the chlorohydrin intermediate, and (2) the intermediate is dehydrohalogenated with sodium hydroxide to yield the aliphatic glycidyl ether. A prominent side-reaction is the conversion of aliphatic hydroxyl groups (formed by the initial reaction) into chloromethyl groups by epichlorohydrin. The aliphatic glycidyl ether resins are used as flexibilizers for aromatic resins and as reactive diluents to reduce viscosities in resin systems. 

This material can be prepared, e.g, by reaction of prednisolone-21-chloroacetate in solvent with the sodium or potassium salt of the corresponding aliphatic or aromatic acid, or by reaction of prednisolone with the chloride of the corresponding acyl-glycolic acid, in the presence of a hydrochloric acid acceptor. 

The nitrosation of amides may also be carried out with nitrosyl chloride.2 Related methods of deamination of aliphatic amines are the triazene3 and nitrous acid methods4... 

NMe is now commercially available and is prepd by the vapor phase nitration of methane at a ratio of 9 moles of methane to I mole of nitric acid at 475° and a residence time of 0.18sec (Ref 12) or by the similar nitration of aliphatic hydrocarbons (Ref 8). Other prepns are from Me sulfate and Na nitrite (Ref 26) by the oxidn of Me amine with dinitrogen trioxide in the gas phase or in methylene chloride, yield 27%... 

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