Hydrochloric Acid → HCID 19024531, compound

Temperature

55 °C

A mixture of 36.5 g of 4-methoxycarbonyl-5-{2-(benzyloxycarbonylamino)ethyl}oxazole, 90 ml of concentrated hydrochloric acid and 270 ml of methanol was stirred at 55° C. for 6 hours. After removing the solvent, the residue was dissolved in tetrahydrofuran, and the solution was neutralized with 21 ml of triethylamine. Further, the solution was cooled to 0° C., and to the solution was added 450 ml of formic acid and was added dropwise 150 ml of acetic anhydride at the same temperature. The mixture was stirred at 10° C. for 3 hours, and ice water was added thereto. The solvent was removed, and then the residue was dissolved in ethyl acetate. The mixture was washed and dried, and then the solvent was removed. The residue was purified by silica gel chromatography to obtain 20 g of methyl 3-oxo-5-(benzyloxycarbonylamino)-2-(formylamino)pentanoate as a colorless oily product.

1. customAfter removing the solvent
2. dissolutionthe residue was dissolved in tetrahydrofuran
3. temperatureFurther, the solution was cooled to 0° C.
4. additionto the solution was added 450 ml of formic acid
5. additionwas added dropwise 150 ml of acetic anhydride at the same temperature
6. stirringThe mixture was stirred at 10° C. for 3 hours
7. additionice water was added
8. customThe solvent was removed
9. dissolutionthe residue was dissolved in ethyl acetate
10. washThe mixture was washed
11. customdried
12. customthe solvent was removed
13. customThe residue was purified by silica gel chromatography

ORD record

ord-841b436c3d8644dfa05e98e67b4f7f5c

Source dataset

uspto-grants-1994_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05312826