Propionyl chloride → HCID 11390057, compound

(194) A solution of 2-(oxazol-5-yl)pyridine (98 mg, 0.67 mmol) in anhydrous THF (5 mL) cooled to −75° C. under N2 was treated with n-BuLi (2.5 M in hexanes, 1.1 equiv, 0.74 mmol, 0.3 mL), and stirred for 20 min. ZnCl2 (0.5 M in THF, 2.0 equiv, 1.34 mmol, 2.7 mL) was added at −75° C., and stirred for 45 min at 0° C. Cul (1.0 equiv, 0.67 mmol, 128 mg) was added, and the solution was stirred for 10 min at 0° C. Propionyl chloride (2.0 equiv, 1.34 mmol, 124 mg, 0.12 mL) was added and the solution was stirred for 1 h at 0° C. The reaction was diluted with EtOAc (10 mL), and washed with 15% aqueous NH4OH (1×10 mL), H2O (1×10 mL), and saturated aqueous NaCl (1×10 mL). The organic layer was dried (Na2SO4), filtered, and concentrated under reduced pressure. Flash chromatography (SiO2, 2.5 cm×17.5 cm, 20% EtOAc-hexanes) afforded 1-[5-(pyridin-2-yl)oxazol-2-yl]propan-1-one (194) (89 mg, 0.44 mmol, 65% yield) as a light brown powder: mp 65-67° C.; 1H NMR (CDCl3, 250 MHz) d 8.65-8.62 (m, 1H), 7.86-7.75 (m, 3H), 7.31-7.26 (m, 1H), 3.18-3.08 (m, 2H), 1.29-1.21 (m, 3H); 13C NMR (CDCl3, 62.5 MHz) d 188.8, 161.9, 157.2, 150.1, 146.3, 136.9, 126.8, 124.0, 120.3, 32.5, 7.8; IR (KBr) u. 2935, 2862, 1699, 1471, 1426, 1377 cm−1; MALDI-FTMS (DHB) m/z 203.0818 (C11H10N2O2+H+ requires 203.0815).

1. stirringstirred for 45 min at 0° C
2. additionCul (1.0 equiv, 0.67 mmol, 128 mg) was added
3. stirringthe solution was stirred for 10 min at 0° C
4. stirringthe solution was stirred for 1 h at 0° C
5. washwashed with 15% aqueous NH4OH (1×10 mL), H2O (1×10 mL), and saturated aqueous NaCl (1×10 mL)
6. dry with materialThe organic layer was dried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure

ORD record

ord-653a912a170e471c968393f602fec2ec

Source dataset

uspto-grants-2010_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07662971B2