Water → 1-(4-Pyridyl)-2,3-bis(methoxycarbonyl)-6,7-dimethoxynaphthalene

HRID 324035

Reaction equation

HRID 324035 reaction equation
CO[CH:3](OC)[C:4]1[C:9]([C:10]2[CH:15]=[CH:14][N:13]=[CH:12][CH:11]=2)=[CH:8][C:7]([O:16][CH3:17])=[C:6]([O:18][CH3:19])[C:5]=1CO.[CH3:24][O:25][C:26](=[O:33])/[CH:27]=[CH:28]\[C:29]([O:31][CH3:32])=[O:30].[CH3:34]S(O)(=O)=O.O>C(O)(=O)C.C1(C)C=CC=CC=1>[N:13]1[CH:12]=[CH:11][C:10]([C:9]2[C:4]3[C:3](=[CH:8][C:7]([O:16][CH3:17])=[C:6]([O:18][CH3:19])[CH:5]=3)[CH:34]=[C:27]([C:26]([O:25][CH3:24])=[O:33])[C:28]=2[C:29]([O:31][CH3:32])=[O:30])=[CH:15][CH:14]=1

Participants

7

Reactant 4

HCID 962WaterHCID 6395Methanesulfonic AcidHCID 5271565Dimethyl maleateHCID 220073783,4-Dimethoxy-6-(4-pyridyl) hydroxymethylbenzaldehyde dimethylacetal

Product 1

HCID 117286421-(4-Pyridyl)-2,3-bis(methoxycarbonyl)-6,7-dimethoxynaphthalene

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 1140TolueneSolvent

Procedure

To a solution of 3,4-dimethoxy-6-(4-pyridyl)hydroxymethylbenzaldehyde dimethyl acetal (18.4 g) in a mixture of acetic acid (50 ml) and toluene (50 ml) is added maleic acid dimethyl ester (8.64 ml), and the mixture is refluxed for one hour. To the mixture is added methanesulfonic acid (9.33 ml), and the mixture is refluxed for 8 hours while the generated water is removed by using a Dean-stark apparatus. The mixture is cooled to room temperature and concentrated. The residue is dissolved in chloroform, and the pH value thereof is adjusted to pH 8 with an aqueous potassium carbonate solution. The mixture is extracted with chloroform, and the extract is washed, dried, concentrated, and the residue is crystallized from ether to give 1-(4-pyridyl)-2,3-bis(methoxycarbonyl)-6,7-dimethoxynaphthalene (13.5 g).

Workup

  1. temperaturethe mixture is refluxed for one hour
  2. customis removed
  3. concentrationconcentrated
  4. dissolutionThe residue is dissolved in chloroform
  5. extractionThe mixture is extracted with chloroform
  6. washthe extract is washed
  7. customdried
  8. concentrationconcentrated
  9. customthe residue is crystallized from ether

Sources & evidence

ORD record
ord-9155ad3721b84f87879551e41d65dcde
Source dataset
uspto-grants-2001_04
Patent number
US06214996B1

Linked notes

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