Ammonium Hydroxide → 1-ethyl-4-chloro-6,7-dimethoxy-1H-pyrazolo[3,4-b]quinoline

HRID 1586178Notes

Reaction equation

HRID 1586178 reaction equation
[CH2:1]([N:3]1[C:7]([NH:8][C:9]2[C:10](=[CH:14][C:15]([O:20][CH3:21])=[C:16]([O:18][CH3:19])[CH:17]=2)[C:11](O)=O)=[CH:6][CH:5]=[N:4]1)[CH3:2].O=P(Cl)(Cl)[Cl:24].[NH4+].[OH-]>>[CH2:1]([N:3]1[C:7]2=[N:8][C:9]3[C:10]([C:11]([Cl:24])=[C:6]2[CH:5]=[N:4]1)=[CH:14][C:15]([O:20][CH3:21])=[C:16]([O:18][CH3:19])[CH:17]=3)[CH3:2]

Participants

4

Reactant 3

HCID 14923Ammonium HydroxideHCID 24813Phosphorus oxychlorideHCID 21217688N-(1-ethylpyrazol-5-yl)-4,5-dimethoxyanthranilic acid

Product 1

HCID 212176831-ethyl-4-chloro-6,7-dimethoxy-1H-pyrazolo[3,4-b]quinolineYield 62%

Procedure

A mixture of N-(1-ethylpyrazol-5-yl)-4,5-dimethoxy anthranilic acid (12.8 g, 44 mmol) and POCl3 (75 ml) is refluxed for 8 hours. The reaction mixture is cooled to room temperature, poured into ice water and neutralized with concentrated NH4OH. The mixture is extracted with CH2Cl2, and the CH2Cl2 layer is dried over MgSO4 and evaporated to dryness. The residue is purified by column chromatography on silica gel eluting with CH2Cl2 /ether (9/1) to afford 8.0 g (62%) of 1-ethyl-4-chloro-6,7-dimethoxy-1H-pyrazolo[3,4-b]quinoline.

Workup

  1. temperatureis refluxed for 8 hours
  2. extractionThe mixture is extracted with CH2Cl2
  3. dry with materialthe CH2Cl2 layer is dried over MgSO4
  4. customevaporated to dryness
  5. customThe residue is purified by column chromatography on silica gel eluting with CH2Cl2 /ether (9/1)

Sources & evidence

ORD record
ord-f3b9e6bb42364765b50c2d75ac59d2c0
Source dataset
uspto-grants-1999_08
Patent number
US05942520

Reaction notes

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