Nitrogen → Ethyl 2-acetyloxazole-4-carboxylate

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of NaIO4 (23 g, 108 mmol) in water (150 mL) was slowly added to a vigorously stirred suspension of silica gel (110 g) in acetone (500 mL). The mixture was then concentrated under reduced pressure and the lumpy solid slurried in CH2Cl2 and the solvent was evaporated under reduced pressure. CH2Cl2 (500 mL) was added and the reaction mixture was treated at rt with (E)-2-(1-phenylprop-1-en-2-yl)oxazole-4-carboxylic acid ethyl ester (8.3 g, 32 mmol) and RuCl3 hydrate (1.1 g, 2 mmol). The reaction mixture was stirred at rt in the dark for 60 min, filtered and concentrated under reduced pressure. Purification of the residue by FC (1:0 to 1:5 petroleum ether-Et2O) gave the title compound as a pale yellow solid. TLC:rf (1:1 EA-Hept)=0.52. LC-MS-conditions 01: tR=0.70 min; [M+H]+=183.99.

1. concentrationThe mixture was then concentrated under reduced pressure
2. customthe lumpy solid slurried in CH2Cl2 and the solvent was evaporated under reduced pressure
3. additionCH2Cl2 (500 mL) was added
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customPurification of the residue by FC (1:0 to 1:5 petroleum ether-Et2O)

ORD record

ord-bbe1bc029f3445519a6ae3d45a879f44

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08563714B2