Ethanol → HCID 19610839, compound

HRID 1602213Notes

Reaction equation

HRID 1602213 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)=[C:15]([CH3:21])[CH:14]=[CH:13][CH:12]=2.C([OH:25])C>>[O:20]=[C:17]1[C:18]2[N:1]=[C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][N:3]3[C:9]=2[C:10](=[O:22])[C:11]2[CH:12]=[CH:13][CH:14]=[C:15]([CH3:21])[C:16]1=2.[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[C:15]([CH3:21])=[CH:14][CH:13]=[CH:12][C:11]1=2.[O:20]=[C:17]1[C:16]2[C:15]([CH3:21])=[CH:14][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 117592921,4-Naphthalenedione, 2,3-dibromo-5-methyl-

Product 3

HCID 19610839HCID 19610839, compoundHCID 19610844HCID 19610844, compoundHCID 19610858HCID 19610858, compound

Procedure

2.72 g (28.88 mmol, 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-5-methylnaphthalene 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-5-methylnaphthalene that did not react is eliminated by precipitation in a CH2Cl2 /heptane, 80/20 mixture. The raw product is purified by chromatography on a preparation plate (support: silica SIL G-200 UV254 2 mm; eluant: CH2Cl2 /EtOH, 97/3) to produce 6,11-dihydro-6,11-dioxo-7-methylnaphtho[2',3':4,5] imidazo-[1,2-a]pyridine or 6,11-dihydro-6,11-dioxo-10-methylnaphtho[2',3':4,5]imidazo[1,2-a]pyridine or 5,6-dihydro-5,6-dioxo-4-methylnaphtho[1',2':4,5]-imidazo[1,2-a]pyridine in the form of yellowish-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-5-methylnaphthalene that did not react
  4. customis eliminated by precipitation in a CH2Cl2 /heptane, 80/20 mixture
  5. customThe raw product is purified by chromatography on a preparation plate (support: silica SIL G-200 UV254 2 mm; eluant: CH2Cl2 /EtOH, 97/3)

Sources & evidence

ORD record
ord-6005ce371456481cab73413496bba1ee
Source dataset
uspto-grants-1999_11
Patent number
US05981544

Reaction notes

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