Реакция #64876

ord-a95fe5a451304b06873d2b8e80483925

Условия реакции

Подробные условия
See reaction.notes.procedure_details.

Обработка

  1. 1
    workup.WAITis then continued for 3 hours at 0°-5° C.
  2. 2
    ПромывкаThe organic phase is washed with water
  3. 3
    Сушкаdried over sodium sulfate
  4. 4
    Концентрированиеconcentrated

Методика

At 0°-5° C., 1.2 g of a sodium hydride dispersion (80 %) are added in portions to a solution of 8.6 g of 4-hydroxy-pyrazolidine-N,N'-dicarboxylic acid di-tert-butyl ester in 90 ml of N,N-dimethylformamide. After stiffing for 30 minutes at 0°-5° C., a solution of 2.5 ml of methyl iodide in 10 ml of N,N-dimethylformamide is added dropwise thereto. Stirring is then continued for 3 hours at 0°-5° C. and then 500 ml of diethyl ether are added thereto. The organic phase is washed with water, dried over sodium sulfate and concentrated to yield 8.0 g of the desired product, 4-methoxy-pyrazolidine-N,N'-dicarboxylic acid di-tertbutyl ester, in the form of a yellow oil.

Источник

DOI: 10.6084/m9.figshare.5104873.v1Патент: US05416065uspto-grants-1995_05