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ChemicalBook CAS DataBase List Ethyl oxazole-4-carboxylate
23012-14-8

Ethyl oxazole-4-carboxylate synthesis

6synthesis methods
-

Yield:23012-14-8 84%

Reaction Conditions:

Stage #1: 1,1'-carbonyldiimidazolewith formic acid in tetrahydrofuran; for 0.5 h;
Stage #2: Glycine ethyl ester isocyanatewith triethylamine in tetrahydrofuran at 20; for 1 h;Heating / reflux;

Steps:



To a sol. of formic acid (8.62 mL, 228 mmol) in dry THF (200 mL) was added portionwise CDI (37.05 g, 228 mmol), whereas a gas evolution occurred. The mixture was stirred for 30 min, and a sol. of ethyl isocyanoacetate (25 mL, 228 mmol) in Et3N (60.5 mL, 434mmol) was added to the reaction mixture. The mixture was stirred at rt for 1 h, then under reflux overnight. The reaction mixture was allowed to cool to rt. Water was added, and the mixture was extracted with Et2O (3x). The combined org. extracts were dried over MgSO4, filtered and concentrated. Purification of the residue by FC (EtOAc / heptane; 1:5 -> 1:3 - 1:1) yielded the title compound (27.2 g, 84%). LC-MS: tR = 0.58, ES+: 142.07.

References:

WO2006/21402,2006,A1 Location in patent:Page/Page column 33-34

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