Reacción #7737

Ecuación de reacción

HCl

4-methylenepyrazolidine-1,2-dicarboxylic acid 1-benzyl ester 2-tert-butyl ester

thionyl chloride

→

desired product

Rendimiento 97.0%

4-methylene-pyrazolidine-1-carboxylic acid 1-benzyl ester

Rendimiento 97.0%

Disolventes

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroConcentration of the reaction in vacuo
2. 2
   Otroaffords a yellow oil which
3. 3
   Otrocrystallizes

Procedimiento

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.

Fuente