Substitution of halogen atom in ?-halonitro compounds of the aliphatic series
摘要:
Ethyl alpha-halo-alpha-nitropropionate and -butyrate were prepared by alkylating ammonium salts of ethyl bromo- and chloronitroacetates. The addition of alkyl acrylates to alkyl chloronitroacetates or their salts gives dialkyl alpha-chloro-alpha-nitroglutarates. Sodium salts of ethyl alpha-nitro-alpha-sulfo-beta-hydroxypropionate and -butyrate were obtained by the sulfo-dehalogenation of ethyl alpha-chloro-alpha-nitro-beta-hydroxypropionate and -butyrate with sodium dithionite. Esters of a-amino acid hydrochlorides were prepared by the reduction of alkyl alpha-chloro-alpha-nitrocarboxylates. The hydrogenation of alkyl nitrosulfoacetates leads to the corresponding disodium salts of alkyl aminodisulfoacetates and piperazine-2,5-dione.
Aliphatic nitro compounds are easily halogenated by N-chloro or N-bromosuccinimide in protic solvents to give the practically pure gem-halonitro compounds.
Titanium(IV) Enolates of 2-Nitrocarboxylic Esters and Their Oxidative Chlorination. A Convenient Route to α-Chloro-α-nitrocarboxylates
作者:Dariusz Cież、Justyna Kalinowska-Tłuścik
DOI:10.1055/s-0031-1290081
日期:2012.1
A new method for the synthesis of 2-chloro-2-nitrocarboxylic esters from 2-nitrocarboxylates is described. The procedure consists of the oxidative chlorination of titanium(IV) enolates of 2-nitro esters in the presence of ammonium nitrate. Esters of 2-chloro-2-nitrocarboxylic acids are formed in very good to quantitative yields. Application of this method for the chlorination of α,α′-dinitrodicarboxylates