Water → HCID 23061941, compound

Temperature

0 °C

Ethyl 2-[2-(1H-benzimidazol-1-yl)-4-(4-chlorophenyl)-5-oxazolyl]-2-oxoacetate (3.50 g) was dissolved in a mixed solvent of tetrahydrofuran (60 mL)-ethanol (20 mL), sodium borohydride (100 mg) was added at 0° C. and the mixture was stirred at 0° C. for 1 hr. The reaction mixture was poured into water, and the precipitated solid was collected by filtration and dried. The obtained solid was added to thionyl chloride (10 mL) at 0° C., and the mixture was stirred at room temperature for 1 hr. The reaction mixture was concentrated and poured into 10% aqueous sodium hydrogen carbonate solution and the mixture was extracted with ethyl acetate. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and concentrated. The residue was dissolved in acetic acid (50 mL) and zinc powder (10 g) was added. The mixture was stirred with heating under reflux for 30 min. Insoluble material was removed by filtration, and the filtrate was concentrated and poured into 10% aqueous sodium hydrogen carbonate solution. The mixture was extracted with ethyl acetate, and the organic layer was washed with water, dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by silica gel column chromatography and ethyl 2-[2-(1H-benzimidazol-1-yl)-4-(4-chlorophenyl)-5-oxazolyl]acetate (2.07 g, 61%) was obtained as crystals from a fraction eluted with acetone-hexane (1:2, volume ratio). Recrystallization from acetone-isopropyl ether gave colorless needle crystals. melting point: 152–153° C.

1. additionwas added at 0° C.
2. filtrationthe precipitated solid was collected by filtration
3. customdried
4. additionThe obtained solid was added to thionyl chloride (10 mL) at 0° C.
5. stirringthe mixture was stirred at room temperature for 1 hr
6. concentrationThe reaction mixture was concentrated
7. additionpoured into 10% aqueous sodium hydrogen carbonate solution
8. extractionthe mixture was extracted with ethyl acetate
9. washThe organic layer was washed with water
10. dry with materialdried over anhydrous magnesium sulfate
11. concentrationconcentrated
12. dissolutionThe residue was dissolved in acetic acid (50 mL)
13. additionzinc powder (10 g) was added
14. stirringThe mixture was stirred
15. temperaturewith heating
16. temperatureunder reflux for 30 min
17. customInsoluble material was removed by filtration
18. concentrationthe filtrate was concentrated
19. additionpoured into 10% aqueous sodium hydrogen carbonate solution
20. extractionThe mixture was extracted with ethyl acetate
21. washthe organic layer was washed with water
22. dry with materialdried over anhydrous magnesium sulfate
23. concentrationconcentrated
24. customThe residue was purified by silica gel column chromatography

ORD record

ord-dcecf77a1dce4cbb9eda7a43178d3556

Source dataset

uspto-grants-2007_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07183276B2