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

HRID 1586168Notes

Reaction equation

HRID 1586168 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) is refluxed overnight. The reaction mixture is poured into ice water (500 ml), stirred for 20 minutes, and then NH4OH is added until a pH of 8-10 is obtained. The mixture is stirred for 0.5 hours, and then the solid that forms is collected by filtration. The solid is 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. temperatureis refluxed overnight
  2. customis obtained
  3. stirringThe mixture is stirred for 0.5 hours
  4. filtrationthe solid that forms is collected by filtration
  5. dissolutionThe solid is dissolved in CH2Cl2
  6. dry with materialdried over MgSO4
  7. custompurified by column chromatography on silica gel eluting with 30% hexane/ethyl acetate

Sources & evidence

ORD record
ord-a370aa9e61d44fc18d842c44b29bb0ac
Source dataset
uspto-grants-1999_08
Patent number
US05942520

Reaction notes

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