DIMETHYL NITROSUCCINATE

DIMETHYL NITROSUCCINATE [Butanedioic acid, 2-nitro-, dimethyl ester]... 

After dilution with 200 ml. of benzene, the solution is transferred to a 2-1. separatory funnel containing 800 ml. of ice water and shaken thoroughly. The aqueous layer is separated, acidified to pH 3-4 with 2-3 ml. of concentrated hydrochloric acid, and extracted with three 100-ml. portions of benzene. All the organic layers are then combined and dried over anhydrous sodium sulfate. Filtration and concentration of the solution with a rotary evaporator, followed by exposure to high vacuum for 2-3 hours, affords 17.3-19.3 g. of the crude product (Note 3). Low-boiling impurities are removed by vacuum distillation (Note 4), the residual oil (14-15 g.) is transferred to a 50-ml. flask equipped with a short-path distillation apparatus, and vacuum distillation is continued. A forerun is taken until no rise in boiling point is observed, and then 7.2-8.6 g. (23-27%) of dimethyl nitrosuccinate is collected as a colorless oil, b.p. 85° (0.07 mm.), 1.4441 (Note 5). 

Dimethylmaleate, 58,74 D1METHYL(METHYLENE)AMM0N1UM TRIFLUOROACETATE, 59, 153 o-Dimethyl 2-nitropentanedioate, 57, 62 Dimethyl 4-nitropimelate, 56, 39 DIMETHYL NITROSUCCINATE, 57, 60... 

---