Ammonium Chloride → 1-[8-Amino-2-(4-fluorophenyl)imidazo[1,2-a)pyridin-3-yl]ethanone

HRID 456685Notes

Reaction equation

HRID 456685 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[N:9]=[C:10]3[C:15]([N+:16]([O-])=O)=[CH:14][CH:13]=[CH:12][N:11]3[C:19]=2[C:20](=[O:22])[CH3:21])=[CH:4][CH:3]=1.[Cl-].[NH4+]>CO.[Fe]>[NH2:16][C:15]1[C:10]2[N:11]([C:19]([C:20](=[O:22])[CH3:21])=[C:8]([C:5]3[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=3)[N:9]=2)[CH:12]=[CH:13][CH:14]=1

Participants

5

Reactant 2

HCID 25517Ammonium ChlorideHCID 695493021-[2-(4-Fluorophenyl)-8-nitroimidazo[1,2-a]pyridin-3-yl]ethanone

Product 1

HCID 695497661-[8-Amino-2-(4-fluorophenyl)imidazo[1,2-a)pyridin-3-yl]ethanoneYield 70.9%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 887MethanolSolvent2×

Procedure

A solution of 1-[2-(4-fluorophenyl)-8-nitroimidazo[1,2-α]pyridin-3-yl]ethanone (100 mg, 0.33 mmol) in methanol (3 mL) was added to a suspension of iron (93 mg, 1.7 mmol) and ammonium chloride (149 mg, 2.8 mmol) in aqueous methanol. This reaction mixture was heated to reflux for 10 hours. The reaction mixture was filtered and the filtrate concentrated under reduced pressure to a solid. This solid was purified by silica gel chromatography (5% methanol in dichloromethane) to give 63 mg (70%) of 1-[8-amino-2-(4-fluorophenyl)imidazo[1,2-α]pyridin-3-yl]ethanone as a foam. 1H NMR (CDCl3): δ 9.21 (d, 1H), 7.61 (m, 2H), 7.25 (m, 2H), 6.94 (t, 1H) 6.72 (d, 1H), 4.63 (broad s, 2H), 2.19 (s, 3H); MS m/z 270 (M+1).

Workup

  1. temperatureThis reaction mixture was heated
  2. temperatureto reflux for 10 hours
  3. filtrationThe reaction mixture was filtered
  4. concentrationthe filtrate concentrated under reduced pressure to a solid
  5. customThis solid was purified by silica gel chromatography (5% methanol in dichloromethane)

Sources & evidence

ORD record
ord-ae9679ebf79f4ee5b567661d24151925
Source dataset
uspto-grants-2007_03
Patent number
US07186714B2

Reaction notes

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