2,3-Dimethoxy-p-benzoquinone → Lonapalene

HRID 2107350Notes

Reaction equation

HRID 2107350 reaction equation
[CH3:1][O:2][C:3]1[C:4]([CH:6]=[CH:7][C:8](=[O:12])[C:9]=1[O:10][CH3:11])=[O:5].[Cl:13][C:14](=[CH2:19])[CH:15]=[CH:16]OC>ClCCl>[Cl:13][C:14]1[CH:19]=[C:6]2[C:7](=[CH:16][CH:15]=1)[C:8]([O:12][C:3](=[O:2])[CH3:9])=[C:9]([O:10][CH3:11])[C:3]([O:2][CH3:1])=[C:4]2[O:5][C:4](=[O:5])[CH3:6]

Participants

4

Reactant 2

HCID 765652,3-Dimethoxy-p-benzoquinoneHCID 542901063-Chloro-1-methoxybuta-1,3-diene

Product 1

HCID 56237LonapaleneYield 117.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A dichloromethane (10 ml) solution of 2,3-dimethoxybenzo-1,4-quinone (1.0 g, 5.9 mmol) and 3-chloro-1-methoxy-1,3-butadiene (1.4 g, 12.0 mmol) is stirred for 24 hours at room temperature under an inert atmosphere. After this time, 80 mg of d,1-camphorsulfonic acid is added and the solution is stirred an additional 12 hours. The mixture is then concentrated and subsequently dissolved in pyridine (15 ml) and acetic anhydride (3.0 g). After stirring for five hours under an inert atmosphere, the solution is concentrated to dryness and taken up in dichloromethane. The organics are washed with water, brine, and then dried (sodium sulfate) and concentrated to afford 1.17 g (58%) of pure 6-chloro-1,4-diacetoxy-2,3-dimethoxynaphthalene.

Workup

  1. concentrationThe mixture is then concentrated
  2. dissolutionsubsequently dissolved in pyridine (15 ml)
  3. stirringAfter stirring for five hours under an inert atmosphere
  4. concentrationthe solution is concentrated to dryness
  5. washThe organics are washed with water, brine
  6. dry with materialdried (sodium sulfate)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-0532a38e91ac40a2b00d5333200d15a6
Source dataset
uspto-grants-1990_06
Patent number
US04933489

Reaction notes

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