Modifications with methyl cyanide

Meperidine hydrochloride (the full name) is a synthetic opioid. It is synthesized by the reaction of chemicals not found in opium. Specifically, meperidine hydrochloride is produced by the reaction of dichlorodi-ethyl methylamine with benzyl cyanide, to produce ethyl l-methyl-4-phenyl-isonipecotate hydrochloride (meperidine s chemical name). Some references to meperidine classify it as a totally synthetic opioid. Semi-synthetic opioids are produced by using one of the opiates as a starting material. Two examples of semi-synthetic opioids are hydrocodone and heroin. Hydrocodone is produced by the chemical modification of codeine, while heroin is made by chemically altering morphine. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

This method is a modification of Robinson s adaptation of that of Polstorff and Meyer. Methoxyacetonitrile has been made by methylating hydroxyacetonitrile with dimethyl sulfate by treatment of copper, mercury, or silver cyanide with chloromethyl ether and by dehydration of methoxyacetamide with phosphorus pentoxide. ... 

The Pachter modification of the Timmis synthesis is performed in the presence of cyanide ion,129 products other than those expected being obtained. For example, the condensation of phenylacetonitrile with 5-nitroso-2-phenylpyrimidine-4,6-diamine in the presence of cyanide ion gives, not 7-methyl-2,6-diphenylpteridin-4-amine but 2,6-diphenylpteridine-4,7-diamine (5).121 The mechanism of the reaction is still uncertain, but it may involve nucleophilic addition of cyanide ion to the Schiff base formed by condensation between the nitroso group and the active methylene, cyclization to yield a dihydropteridine, and subsequent elimination. 

Ethyne may be condensed first with the alkyl halide to give H3C [CH2]a C=CH or with the difunctional entity to give Hcic(CH2)yY. The carboxyl group can be generated by oxidation of an alcohol or by reaction of halide with cyanide and then with acidic methanol to give a methyl ester. Condensation with acetylene or an ethynyl compound requires the sodium or lithium derivative and is usually conducted in liquid ammonia. Modification of this approach is necessary when the unsaturated centre is close to either end of the molecule. 

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