Reaction #640605

Reaction equation

6,7-dihydro-4H-isoxazolo[4,5-c]pyridine-3,5-dicarboxylic acid 3-ethyl ester 5-tert-butyl ester

lithium hydroxide

→

6,7-dihydro-4H-isoxazolo[4,5-c]pyridine-3,5-dicarboxylic acid 5-tert-butyl ester

Solvents

EtOH

Conditions

Workup

1. 1
   OtherThe solvent was removed under a vacuum
2. 2
   workup.DISSOLUTIONthe residue redissolved in a mixture of water/citric acid (pH=4) and ether
3. 3
   OtherThe organic phase was separated off
4. 4
   Dryingdried over magnesium sulfate
5. 5
   Otherthe solvent was removed under a vacuum

Procedure

A mixture of 7.31 g (25 mmol) of 6,7-dihydro-4H-isoxazolo[4,5-c]pyridine-3,5-dicarboxylic acid 3-ethyl ester 5-tert-butyl ester (E), 43 g (30 mmol) of lithium hydroxide and 75 mL of EtOH was stirred at RT for 12 h. The solvent was removed under a vacuum and the residue redissolved in a mixture of water/citric acid (pH=4) and ether. The organic phase was separated off, dried over magnesium sulfate and the solvent was removed under a vacuum. 6.65 g (99% of theoretical) of the desired product 6,7-dihydro-4H-isoxazolo[4,5-c]pyridine-3,5-dicarboxylic acid 5-tert-butyl ester (F) were obtained in the form of a yellow oil which crystallised at RT.

Source