Sodium hydride → Methyl 1-amino-3-chloro-1h-pyrrole-2-carboxylate

To a suspension of sodium hydride (60 percent, 1.5 g, 37.5 mmol) in DMF (250 mL) was added methyl 3-chloro-1H-pyrrole-2-carboxylate (5.0 g, 31.3 mmol) at 0° C., and the mixture was stirred for 25 min, followed by the addition of O-(diphenylphosphoryl)hydroxylamine (10.0 g, 43.75 mmol). The reaction mixture was stirred at RT for 4 h and quenched by aq. Na2SO3 solution. After stirred for another 5 min, the mixture was extracted with EtOAc (3×300 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated to give crude product as a brown oil, which was purified by chromatography purification on silica gel (PE:EA=4:1) to obtain the title compound (5.00 g, 91%) as a white solid. MS (ES+) C6H7ClN2O2 requires: 174, 176. found: 175, 177 [M+H]+.

1. stirringThe reaction mixture was stirred at RT for 4 h
2. customquenched by aq. Na2SO3 solution
3. stirringAfter stirred for another 5 min
4. extractionthe mixture was extracted with EtOAc (3×300 mL)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated
9. customto give crude product as a brown oil, which
10. customwas purified by chromatography purification on silica gel (PE:EA=4:1)

ORD record

ord-381a8a5d8a2548ecae4fa94a30e81e31

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09200002B2