Nitrogen → Ethyl 2-formyl-1,3-oxazole-4-carboxylate

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of NaIO4 (3.21 g, 15.00 mmol) in water (26.0) mL was slowly added to a vigorously stirred suspension of silica gel (15.0 g) in acetone (60.0 mL). The mixture was then concentrated under reduced pressure and the lumpy solid slurred in CH2Cl2 and the solvent was evaporated under reduced pressure. CH2Cl2 (40.0 mL) was added and the reaction mixture was treated at rt with (E)-2-styryl-oxazole-4-carboxylic acid ethyl ester (1.22 g, 5.00 mmol) and RuCl3 hydrate (82 mg, 0.15 mmol). The reaction mixture was stirred at rt in the dark for 30 min, filtered and concentrated under reduced pressure. Purification of the residue by FC (1:9 to 1:2 EA-Hept) gave the title compound as a yellow solid. TLC: rf (3:2 EA-Hept)=0.21. LC-MS-conditions 02: tR=0.51 min; [M+H2O+H]+=188.50.

1. concentrationThe mixture was then concentrated under reduced pressure
2. customthe lumpy solid slurred in CH2Cl2 and the solvent was evaporated under reduced pressure
3. additionCH2Cl2 (40.0 mL) was added
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customPurification of the residue by FC (1:9 to 1:2 EA-Hept)

ORD record

ord-5df9b627b0f748e9a1993420ad396770

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08674111B2