Sodium Dithionite → HCID 21966509, compound

HRID 2212491Notes

Reaction equation

HRID 2212491 reaction equation
[S:1]([O:11][C:12]1[CH:16]=[CH:15][NH:14][C:13]=1[C:17]([O:19][CH3:20])=[O:18])([C:4]1[CH:10]=[CH:9][C:7]([CH3:8])=[CH:6][CH:5]=1)(=[O:3])=[O:2].[H-].[Na+].[NH2:23]Cl.[O-]S(S([O-])=O)=O.[Na+].[Na+]>CN(C=O)C.O>[NH2:23][N:14]1[CH:15]=[CH:16][C:12]([O:11][S:1]([C:4]2[CH:5]=[CH:6][C:7]([CH3:8])=[CH:9][CH:10]=2)(=[O:2])=[O:3])=[C:13]1[C:17]([O:19][CH3:20])=[O:18]

Participants

7

Reactant 4

HCID 24489Sodium DithioniteHCID 24758Sodium hydrideHCID 25423MonochloramineHCID 21966516HCID 21966516, compound

Product 1

HCID 21966509HCID 21966509, compoundYield 88%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

Solid methyl 3-(tosyloxy)-1H-pyrrole-2-carboxylate (1.33 μm, 4.50 mmole) was added in portions to an ice-cooled suspension of NaH (60% in mineral oil, 234 mg, 5.85 mmole) in dry DMF (15 mL) under a dry N2 atmosphere. Upon completion of the addition, the reaction was removed from the bath and left stirring at RT. After 1 hr, a solution of NH2Cl (59 mL; 0.1 M in Et2O prepared according to J. Chem. Soc. C, 1971, 824; 5.85 mmole) was added and the reaction was left stirring for 1.3 hr. It was then cooled to −5° C. and an aqueous solution of Na2S2O4 (20 mL, 1.0 M) was slowly added over 5 min. Water (60 mL) was added and the bath was removed. After 10 min, this was extracted with EtOAc (2×200 mL) and the organic extracts were washed with brine and dried (Na2SO4). Removal of the solvents followed by flash chromatography on silica gel using step gradient elution (hexane:EtOAc from 100:0 to 70:30) afforded the title compound (1.22 gm, 88% yield) as a solid. 1H NMR (CDCl3): 2.39 (s, 2H), 3.62 (s, 3H), 5.44 (s, 2H), 5.76 (m, 1H), 6.73 (m, 1H), 7.26 (m, 2H), 7.66 (m, 2H); MS: 311 (M+H)+; HPLC Ret Time: 1.28 min (YMC Xterra S7 3.0×50 mm column, 2 min gradient, 5 mL/min).

Workup

  1. temperaturecooled
  2. additionUpon completion of the addition
  3. customthe reaction was removed from the bath
  4. waitleft
  5. waitthe reaction was left
  6. stirringstirring for 1.3 hr
  7. temperatureIt was then cooled to −5° C.
  8. customthe bath was removed
  9. waitAfter 10 min
  10. extractionthis was extracted with EtOAc (2×200 mL)
  11. washthe organic extracts were washed with brine
  12. dry with materialdried (Na2SO4)
  13. customRemoval of the solvents
  14. washfollowed by flash chromatography on silica gel using step gradient elution (hexane:EtOAc from 100:0 to 70:30)

Sources & evidence

ORD record
ord-d3e47c53d7864d42bcf574861b3d0793
Source dataset
uspto-grants-2006_09
Patent number
US07102003B2

Reaction notes

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