Diethyl Oxalate → HCID 68415320, compound

Under anhydrous conditions, a solution of potassium t-butoxide (292 mg, 2.6 mmol) in diethyl ether (100 ml) was cooled to −78° C. and stirred for 10 min under an argon atmosphere. Commercial 2 M LDA in heptane/THF/ethyl benzene (13 ml, 26 mmol) was added by syringe and the mixture stirred for 15 min. 4-Chlorobutyrophenone (5 g, 26 mmol) in diethyl ether (35 ml) was added dropwise over 30 min with stirring. After a further 30 min, diethyl oxalate (3.53 ml, 26 mmol) was added in one portion. The cooling bath was removed and the reaction stirred for 2.5 h after reaching ambient temperature. After standing 3 days, the precipitated brown solid was filtered. The solid was partitioned between 1 M HCl and ethyl acetate. The aqueous layer was extracted two times with ethyl acetate, the combined extracts were washed with brine and dried over sodium sulfate. Evaporation of the solid gave 740 mg (4.6 mmol, 18%) of the title compound as orange oil.

1. stirringthe mixture stirred for 15 min
2. stirringwith stirring
3. waitAfter a further 30 min
4. customThe cooling bath was removed
5. stirringthe reaction stirred for 2.5 h
6. customafter reaching ambient temperature
7. waitAfter standing 3 days
8. filtrationthe precipitated brown solid was filtered
9. customThe solid was partitioned between 1 M HCl and ethyl acetate
10. extractionThe aqueous layer was extracted two times with ethyl acetate
11. washthe combined extracts were washed with brine
12. dry with materialdried over sodium sulfate
13. customEvaporation of the solid

ORD record

ord-17b73b41b25949b7a4bc6aaff8317cc3

Source dataset

uspto-grants-2007_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07265149B2