Réaction #5646

Équation de réaction

diacid

4-(2-methoxy-4-benzyloxyphenyl)pyridine-2,6-dicarboxylic acid

methanol

oxalyl chloride

HCl

→

diester

Rendement 65.0%

4-(2-methoxy-4-benzyloxyphenyl)pyridine-2,6-dicarboxylic acid dimethyl ester

Rendement 65.0%

Solvants

water

CH2Cl2

CH2Cl2

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAfter addition the mixture
2. 2
   TempératureThe resulting homogeneous solution was then cooled in an ice bath
3. 3
   workup.STIRRINGThe resulting mixture was stirred for 30 minutes at room temperature
4. 4
   AutreThe organic phase was removed
5. 5
   Lavagewashed with 10% NaHCO3, water
6. 6
   Séchagedried (Na2SO4) and solvents
7. 7
   Autreremoved
8. 8
   FiltrationThe crude diester (15 g) was purified via plug filtration with SiO2 /EtOAc/CH2Cl2 (20:80)

Mode opératoire

To a suspension of 10 g (0.026 mole) of the diacid 22 in 100 ml of CH2Cl2 and 7 drops of DMF was added, at 0° C., in a dropwise fashion 12 ml (0.138 mole) of oxalyl chloride. After addition the mixture was allowed to come to room temperature with vigorous evolution of HCl gas and stirred for 2 hours. The resulting homogeneous solution was then cooled in an ice bath and 20 ml of methanol in 40 ml of CH2Cl2 was slowly added. The resulting mixture was stirred for 30 minutes at room temperature and poured into 300 ml of water. The organic phase was removed, washed with 10% NaHCO3, water, dried (Na2SO4) and solvents removed. The crude diester (15 g) was purified via plug filtration with SiO2 /EtOAc/CH2Cl2 (20:80) yielding 7.0 g (65%) of the diester (23):NMR (CDCl3 ) 3.85 (s, 3,OCH3), 4.05 (s,6,CO2Me), 5.1 (s,2,OCH2O), 6.7 and 7.4 (m,3,--C6H3O2R2) 7.35 (s,5,--C6H5), 8.5 (s,2,--C5H2N'.

Source