Ethanol → HCID 19610833, compound

HRID 1602214Notes

Reaction equation

HRID 1602214 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.Br[C:9]1[C:10](=[O:22])[C:11]2[C:16]([C:17](=[O:20])[C:18]=1Br)=[CH:15][C:14]([CH3:21])=[CH:13][CH:12]=2.C([OH:25])C>>[O:22]=[C:10]1[C:9]2[N:1]=[C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][N:3]3[C:18]=2[C:17](=[O:20])[C:16]2[CH:15]=[C:14]([CH3:21])[CH:13]=[CH:12][C:11]1=2.[O:22]=[C:10]1[C:11]2[CH:12]=[CH:13][C:14]([CH3:21])=[CH:15][C:16]=2[C:17]2[N:1]=[C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][N:3]3[C:18]=2[C:9]1=[O:25].[O:20]=[C:17]1[C:16]2[CH:15]=[C:14]([CH3:21])[CH:13]=[CH:12][C:11]=2[C:10]2[N:1]=[C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][N:3]3[C:9]=2[C:18]1=[O:25]

Participants

6

Reactant 3

HCID 702EthanolHCID 104392-AminopyridineHCID 15915855HCID 15915855, compound

Product 3

HCID 19610833HCID 19610833, compoundHCID 19610846HCID 19610846, compoundHCID 19610865HCID 19610865, compound

Procedure

2.72 g (28.88 mol, 2.4 eq) of 2-aminopyridine are added twice to a suspension of 4.00 g (12.12 mmol, 1 eq) of 2,3-dibromo-1,4-dihydro-1,4-dioxo-6-methylnaphthalene (No. CAS 72364-92-2) in 500 mL of ethanol. This mixture is brought to reflux for 48 h. After cooling to ambient temperature, the ethanol is eliminated by evaporation, under reduced pressure. The 2,3-dibromo-1,4-dihydro-1,4-dioxo-6-methylnaphthalene that had not reacted is eliminated by precipitation in a CH2Cl2 /heptane, 70/30 mixture. The raw product is purified by two successive chromatographies on a preparation plate (support: silica SIL G-200 UV254 2 mm; eluant first plate: CH2Cl2 /MeOH, 97/3, and eluant second plate: heptane/AcOEt, 50/60) to produce 6,11-dihydro-6,11-dioxo-8-methylnaphtho[2,,3':4,5]imidazo[1,2-a]pyridine, 6,11-dihydro-6,11-dioxo-9-methylnaphtho[2',3':4,5]imidazo[1,2-a] pyridine, 5,6-dihydro-5,6-dioxo-2-methylnaphtho[1',2':4,5] imidazo[1,2-a]pyridine or 5,6-dihydro-5,6-dioxo-3-methylnaphth [1',2':4,5]imidazo[1,2-a]pyridine in the form of orange crystals.

Workup

  1. temperatureto reflux for 48 h
  2. customthe ethanol is eliminated by evaporation, under reduced pressure
  3. customThe 2,3-dibromo-1,4-dihydro-1,4-dioxo-6-methylnaphthalene that had not reacted
  4. customis eliminated by precipitation in a CH2Cl2 /heptane, 70/30 mixture
  5. customThe raw product is purified by two successive chromatographies on a preparation plate (support: silica SIL G-200 UV254 2 mm; eluant first plate: CH2Cl2 /MeOH, 97/3, and eluant second plate: heptane/AcOEt, 50/60)

Sources & evidence

ORD record
ord-fb0f26ac695745bd9fa98a28925d02c6
Source dataset
uspto-grants-1999_11
Patent number
US05981544

Reaction notes

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