Ammonium Chloride → tert-butyl 8-(4-aminophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylate

HRID 2179324Notes

Reaction equation

HRID 2179324 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([S:10]([C:13]2[CH:14]=[CH:15][C:16]3[O:25][C:24]4[CH2:23][CH2:22][N:21]([C:26]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27])[CH2:20][C:19]=4[C:17]=3[CH:18]=2)(=[O:12])=[O:11])=[CH:6][CH:5]=1)([O-])=O.[Cl-].[NH4+]>C(O)C.O.[Fe]>[NH2:1][C:4]1[CH:9]=[CH:8][C:7]([S:10]([C:13]2[CH:14]=[CH:15][C:16]3[O:25][C:24]4[CH2:23][CH2:22][N:21]([C:26]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27])[CH2:20][C:19]=4[C:17]=3[CH:18]=2)(=[O:11])=[O:12])=[CH:6][CH:5]=1

Participants

6

Reactant 2

HCID 25517Ammonium ChlorideHCID 68109579tert-butyl 8-(4-nitrophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylate

Product 1

HCID 68109545tert-butyl 8-(4-aminophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylateYield 88.7%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 702EthanolSolventHCID 962WaterSolvent

Procedure

To a solution of product from step A (96 mg, 0.20 mmol) in ethanol (4.0 mL) and water (2.0 mL) was added iron powder (57 mg, 1.02 mmol) and ammonium chloride (12 mg, 0.22 mmol). After refluxing for 3 h, the reaction mixture was filtered through a bed of celite and the celite bed washed repeatedly with ethyl acetate. The filtrate was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give a crude product which was purified by flash column chromatography (SiO2, 3:2 hexanes/ethyl acetate) to give the product tert-butyl 8-(4-aminophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylate (76 mg, 87%) as an off-white solid: 1H NMR (CDCl3, 300 MHz) δ 8.22-8.19 (m, 1H), 7.88 (dd, J=8.7, 1.8 Hz, 1H), 7.81-7.75 (m, 2H), 7.67 (d, J=8.4 Hz, 1H), 6.97-6.91 (m, 2H), 4.48 (s, 2H), 3.54-3.52 (m, 2H), 3.23-3.16 (m, 2H), 1.55 (s, 9H).

Workup

  1. temperatureAfter refluxing for 3 h
  2. filtrationthe reaction mixture was filtered through a bed of celite
  3. washthe celite bed washed repeatedly with ethyl acetate
  4. dry with materialThe filtrate was dried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customto give a crude product which
  8. customwas purified by flash column chromatography (SiO2, 3:2 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-d15a505c1e6a468e8965046b44e1850f
Source dataset
uspto-grants-2015_06
Patent number
US09067949B2

Reaction notes

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