Reaction #7737

ord-9f5a1084af704e6c96cab63ed63b299d

Reaction equation

Cl
HCl
C=C1CN(C(=O)OCc2ccccc2)N(C(=O)OC(C)(C)C)C1
4-methylenepyrazolidine-1,2-dicarboxylic acid 1-benzyl ester 2-tert-butyl ester
O=S(Cl)Cl
thionyl chloride
→
C=C1CNN(C(=O)OCc2ccccc2)C1
desired product
Yield 97.0%
C=C1CNN(C(=O)OCc2ccccc2)C1
4-methylene-pyrazolidine-1-carboxylic acid 1-benzyl ester
Yield 97.0%

Reactants

Cl
HCl
C=C1CN(C(=O)OCc2ccccc2)N(C(=O)OC(C)(C)C)C1
4-methylenepyrazolidine-1,2-dicarboxylic acid 1-benzyl ester 2-tert-butyl ester
O=S(Cl)Cl
thionyl chloride

Reagents

None

Solvents

CO
methanol

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    OtherConcentration of the reaction in vacuo
  2. 2
    Otheraffords a yellow oil which
  3. 3
    Othercrystallizes

Procedure

To a solution of crude 4-methylenepyrazolidine-1,2-dicarboxylic acid 1-benzyl ester 2-tert-butyl ester, 8, (30 g) in methanol (300 mL) is added thionyl chloride dropwise at 0° C. The reaction is warmed to room temperature and stirred an additional 18 hours. Concentration of the reaction in vacuo affords a yellow oil which crystallizes upon standing to provide 23 g (97% yield) of the desired product as the HCl salt.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US07087615B2uspto-grants-2006_08