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

HRID 375894Notes

Reaction equation

HRID 375894 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) was refluxed for 8 hours. The reaction mixture was cooled to room temperature, poured into ice-water and neutralized with concentrated NH4OH. The mixture was extracted with CH2Cl2 and the CH2Cl2 layer was dried over MgSO4 and evaporated to dryness. The residue was 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. temperaturewas refluxed for 8 hours
  2. extractionThe mixture was extracted with CH2Cl2
  3. dry with materialthe CH2Cl2 layer was dried over MgSO4
  4. customevaporated to dryness
  5. customThe residue was purified by column chromatography on silica gel eluting with CH2Cl2 /ether (9/1)

Sources & evidence

ORD record
ord-3dbf4289629f47e08793903653559276
Source dataset
uspto-grants-1996_01
Patent number
US05488055

Reaction notes

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