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

HRID 1586179Notes

Reaction equation

HRID 1586179 reaction equation
[CH2:1]([N:3]1[C:7]([NH:8][C:9]2[C:10](=[CH:14][CH:15]=[CH:16][C:17]=2[Br:18])[C:11](O)=O)=[CH:6][CH:5]=[N:4]1)[CH3:2].[CH2:19]([N:21]1[C:25]([NH:26][C:27]2[C:28](=[CH:32][C:33]([Br:36])=[CH:34][CH:35]=2)[C:29](O)=O)=[CH:24][CH:23]=[N:22]1)[CH3:20].[NH4+].[OH-].O=P(Cl)(Cl)[Cl:41]>>[CH2:1]([N:3]1[C:7]2=[N:8][C:9]3[C:10]([C:11]([Cl:41])=[C:6]2[CH:5]=[N:4]1)=[CH:14][CH:15]=[CH:16][C:17]=3[Br:18])[CH3:2].[CH2:19]([N:21]1[C:25]2=[N:26][C:27]3[C:28]([C:29]([Cl:41])=[C:24]2[CH:23]=[N:22]1)=[CH:32][C:33]([Br:36])=[CH:34][CH:35]=3)[CH3:20]

Participants

6

Reactant 4

HCID 14923Ammonium HydroxideHCID 24813Phosphorus oxychlorideHCID 19592213N-(1-ethylpyrazol-5-yl)-5-bromoanthranilic acidHCID 21217718N-(1-ethylpyrazol-5-yl)-3-bromoanthranilic acid

Product 2

HCID 195922191-ethyl-4-chloro-6-bromo-1H-pyrazolo[3,4-b]quinolineYield 64%HCID 212176931-ethyl-4-chloro-8-bromo-1H-pyrazolo[3,4-b]quinoline

Procedure

and (c) A mixture of N-(1-ethylpyrazol-5-yl)-3-bromoanthranilic acid and N-(1-ethylpyrazol-5-yl)-5-bromoanthranilic acid (34.8 g, 0.11 mol) and POCl3 (100 ml) is heated at reflux for 8 hours. The reaction mixture is cooled to room temperature, and then is 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 2.7 g of 1-ethyl-4-chloro-8-bromo-1H-pyrazolo[3,4-b]quinoline (labelled as Example 44(b)) and 22.5 g (64%) of 1-ethyl-4-chloro-6-bromo-1H-pyrazolo[3,4-b]quinoline (labelled as Example 44(c)).

Workup

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

Sources & evidence

ORD record
ord-60d14b56bccb490c896381b3a49fab53
Source dataset
uspto-grants-1999_08
Patent number
US05942520

Reaction notes

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