Ethyl 7-(4-(tert-butoxycarbonyl)-2-nitrophenoxy)-6,8-dichlorochroman-4-carboxylate → Ethyl 7-(2-amino-4-(tert-butoxycarbonyl)phenoxy)-6,8-dichlorochroman-4-carboxylate

HRID 1626370Notes

Reaction equation

HRID 1626370 reaction equation
[C:1]([O:5][C:6]([C:8]1[CH:31]=[CH:30][C:11]([O:12][C:13]2[C:22]([Cl:23])=[C:21]3[C:16]([CH:17]([C:24]([O:26][CH2:27][CH3:28])=[O:25])[CH2:18][CH2:19][O:20]3)=[CH:15][C:14]=2[Cl:29])=[C:10]([N+:32]([O-])=O)[CH:9]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2]>C1COCC1.[Cl-].[NH4+].C(OCC)(=O)C.[Zn]>[NH2:32][C:10]1[CH:9]=[C:8]([C:6]([O:5][C:1]([CH3:2])([CH3:4])[CH3:3])=[O:7])[CH:31]=[CH:30][C:11]=1[O:12][C:13]1[C:22]([Cl:23])=[C:21]2[C:16]([CH:17]([C:24]([O:26][CH2:27][CH3:28])=[O:25])[CH2:18][CH2:19][O:20]2)=[CH:15][C:14]=1[Cl:29]

Participants

6

Reactant 1

HCID 67080485Ethyl 7-(4-(tert-butoxycarbonyl)-2-nitrophenoxy)-6,8-dichlorochroman-4-carboxylate

Product 1

HCID 67080422Ethyl 7-(2-amino-4-(tert-butoxycarbonyl)phenoxy)-6,8-dichlorochroman-4-carboxylateYield 86.5%

Reagents, catalysts & solvents 4

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolventHCID 25517Ammonium ChlorideSolvent

Procedure

To a mixture of ethyl 7-(4-(tert-butoxycarbonyl)-2-nitrophenoxy)-6,8-dichlorochroman-4-carboxylate (2.70 g, 5.27 mmol) in 25 mL of THF and 25 mL of saturated ammonium chloride was added zinc dust (3.45 g, 52.7 mmol) under argon. After 1 hour at ambient temperature, the reaction was diluted with ethyl acetate and filtered. The biphasic filtrate was separated and the organic layer was washed with brine. The organic layer was dried over sodium sulfate, filtered and concentrated. The crude product was dissolved in dichloromethane, concentrated onto silica gel and purified by flash column chromatography, eluting with 20% ethyl acetate in hexanes to give ethyl 7-(2-amino-4-(tert-butoxycarbonyl)phenoxy)-6,8-dichlorochroman-4-carboxylate (2.20 g, 86.5% yield) as a white foam. MS (ESI) m/z=482 (M+H).

Workup

  1. filtrationfiltered
  2. customThe biphasic filtrate was separated
  3. washthe organic layer was washed with brine
  4. dry with materialThe organic layer was dried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated
  7. dissolutionThe crude product was dissolved in dichloromethane
  8. concentrationconcentrated onto silica gel
  9. custompurified by flash column chromatography
  10. washeluting with 20% ethyl acetate in hexanes

Sources & evidence

ORD record
ord-0ee7d60f2eb4432bac8da73e3fe1878f
Source dataset
uspto-grants-2014_07
Patent number
US08785445B2

Reaction notes

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