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

HRID 375884Notes

Reaction equation

HRID 375884 reaction equation
[CH2:1]([N:3]1[C:7]([NH:8][C:9]2[C:10](=[CH:14][C:15]([Br:18])=[CH:16][CH:17]=2)[C:11](O)=O)=[CH:6][CH:5]=[N:4]1)[CH3:2].O=P(Cl)(Cl)[Cl:21].[NH4+].[OH-]>>[CH2:1]([N:3]1[C:7]2=[N:8][C:9]3[C:10]([C:11]([Cl:21])=[C:6]2[CH:5]=[N:4]1)=[CH:14][C:15]([Br:18])=[CH:16][CH:17]=3)[CH3:2]

Participants

4

Reactant 3

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

Product 1

HCID 195922191-ethyl-4-chloro-6-bromo-1H-pyrazolo[3,4-b]quinoline

Procedure

A mixture of N-(1-ethylpyrazol-5-yl)-5-bromoanthranilic acid (12.6 g) and POCl3 (30 ml) was refluxed overnight. The reaction mixture was poured into ice-water (500 ml), stirred for 20 minutes, and then NH4OH was added until a pH of 8-10 was obtained. The mixture was stirred for 0.5 hours and then the solid which formed was collected by filtration. The solid was dissolved in CH2Cl2, dried over MgSO4 and purified by column chromatography on silica gel eluting with 30% hexane/ethyl acetate to afford 6.5 g of 1-ethyl-4-chloro-6-bromo-1H-pyrazolo[3,4-b]quinoline, m.p. 117°-118° C.

Workup

  1. temperaturewas refluxed overnight
  2. customwas obtained
  3. stirringThe mixture was stirred for 0.5 hours
  4. customthe solid which formed
  5. filtrationwas collected by filtration
  6. dissolutionThe solid was dissolved in CH2Cl2
  7. dry with materialdried over MgSO4
  8. custompurified by column chromatography on silica gel eluting with 30% hexane/ethyl acetate

Sources & evidence

ORD record
ord-b7990bfbc39f4dbb88b85621dd679584
Source dataset
uspto-grants-1996_01
Patent number
US05488055

Reaction notes

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