Hydrochloric Acid → Methyl 1-[2-(4'-aminobiphenyl-4-yl)-2-oxoethyl]cyclopentanecarboxylate

HRID 30845Notes

Reaction equation

HRID 30845 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([C:10]2[CH:15]=[CH:14][C:13]([C:16](=[O:27])[CH2:17][C:18]3([C:23]([O:25][CH3:26])=[O:24])[CH2:22][CH2:21][CH2:20][CH2:19]3)=[CH:12][CH:11]=2)=[CH:6][CH:5]=1)([O-])=O.Cl>C(O)C.[Fe]>[NH2:1][C:4]1[CH:5]=[CH:6][C:7]([C:10]2[CH:15]=[CH:14][C:13]([C:16](=[O:27])[CH2:17][C:18]3([C:23]([O:25][CH3:26])=[O:24])[CH2:22][CH2:21][CH2:20][CH2:19]3)=[CH:12][CH:11]=2)=[CH:8][CH:9]=1

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 21985829Methyl 1-[2-(4'-nitro-1,1'-biphenyl-4-yl)-2-oxoethyl]cyclopentanecarboxylate

Product 1

HCID 21985765Methyl 1-[2-(4'-aminobiphenyl-4-yl)-2-oxoethyl]cyclopentanecarboxylateYield 80.8%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 702EthanolSolvent

Conditions

Temperature
85 °C

Procedure

To a 100 mL flask fitted with a reflux condenser was added methyl 1-[2-(4′-nitro-1,1′-biphenyl-4-yl)-2-oxoethyl]cyclopentanecarboxylate (1.68 g, 4.40 mmol) dissolved in 85% aqueous ethanol (55 mL), followed by addition of 2 N aqueous hydrochloric acid solution (2.20 mL) and finely powdered iron (0) (2.46 g, 44.1 mmol). The reaction mixture was heated to 85° C. over 2 h. Upon cooling, the darkly-colored reaction mixture was filtered under reduced pressure through 2 cm Celite®/2 cm silica, in order to remove iron particulates and polar impurities. The yellow filtrate was concentrated under reduced pressure, resulting in a solid that was triturated with 20 mL diethyl ether/20 mL hexane to afford methyl 1-[2-(4′-amino-1,1′-biphenyl-4-yl)-2-oxoethyl]cyclopentanecarboxylate as a light tan solid (1.20 g, 76%). LC-MS ret. time 2.71 min, m/z 338.1 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.55-1.84 (overlapping signals, 6H), 2.25-2.35 (m, 2H), 3.44 (s, 2H), 3.67 (s, 3H), 7.40-8.10 (overlapping signals, 8H).

Workup

  1. customTo a 100 mL flask fitted with a reflux condenser
  2. temperatureUpon cooling
  3. filtrationthe darkly-colored reaction mixture was filtered under reduced pressure through 2 cm Celite®/2 cm silica, in order
  4. customto remove iron particulates and polar impurities
  5. concentrationThe yellow filtrate was concentrated under reduced pressure
  6. customresulting in a solid
  7. customthat was triturated with 20 mL diethyl ether/20 mL hexane

Sources & evidence

ORD record
ord-8d73db79b84a456f938b2b17d1f590b1
Source dataset
uspto-grants-2008_09
Patent number
US07423156B2

Reaction notes

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