Sodium Azide → HCID 86687688, compound

In a 10-mL round bottom flask under N2 were dissolved 4-oxazolecarboxylic acid (500 mg, 4.42 mmol) and oxalyl chloride (1.94 mL, 22.1 mmol) with 2 drop of DMF in 10 mL of DCM. The reaction was stirred at rt for 2 h. The reaction mixture was concentrated under reduced pressure and the material was carried forward crude. Under N2, oxazole-4-carbonyl chloride (crude) was dissolved in 10 mL of acetone and treated at 0° C. with a solution of sodium azide (575 mg, 8.84 mmol) in 1.0 mL of water. After 1 h, the reaction mixture was diluted with AcOEt then neutralized with H2O. The aqueous phase was extracted 3× with AcOEt then the organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. The crude oxazole-4-carbonyl azide (590 mg, 4.27 mmol, 97% yield) was carried forward without further purification into the next step. MS (ESI, positive ion) [M+1]+: 139.0.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. dissolutionUnder N2, oxazole-4-carbonyl chloride (crude) was dissolved in 10 mL of acetone
3. waitAfter 1 h
4. extractionThe aqueous phase was extracted 3× with AcOEt
5. dry with materialthe organic layers were dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-5824d11c11d74bf1afe1a03a26f713e8

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09012443B2