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ChemicalBook CAS DataBase List DIETHYL 4-CHLORO-2,6-PYRIDINEDICARBOXYLATE
53389-01-8

DIETHYL 4-CHLORO-2,6-PYRIDINEDICARBOXYLATE synthesis

4synthesis methods
-

Yield: 86%

Reaction Conditions:

Stage #1:Chelidamic acid with trichlorophosphateHeating / reflux;
Stage #2:ethanol with triethylamine in tetrahydrofuran at 0 - 20; for 0.5 h;

Steps:

34.A
Part A; Chelidamic acid 403 (5.00 g, 27.3 mmol) was mixed with 30 mL of POCI3 and heated to reflux overnight. The reaction was then concentrated in vacuo. The residue was dissolved in 50 mL of THF. This solution was added slowly to 200 mL of EtOH at 0 0C. Et3N (25 mL) was carefully added to the EtOH solution. The reaction was allowed to warm to room temperature and stirred for 30 minutes. This mixture was concentrated in vacuo and the residue dissolved in 200 mL of EtOAc. The EtOAc solution was washed with H2O and brine. The organic layer was dried with Na2SO4 and concentrated in vacuo. Recrystallization from EtOH gave 6.08 g of compound 404 in 86 % yields.

References:

SCHERING CORPORATION WO2008/82487, 2008, A2 Location in patent:Page/Page column 155

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