Phosphorus oxychloride → 1-ethyl-4-chloro-6-(methylthio)-1H-pyrazolo[3,4-b]quinoline

HRID 375901Notes

Reaction equation

HRID 375901 reaction equation
[CH2:1]([N:3]1[C:7]([NH:8][C:9]2[C:10](=[CH:14][C:15]([S:18][CH3:19])=[CH:16][CH:17]=2)[C:11](O)=O)=[CH:6][CH:5]=[N:4]1)[CH3:2].O=P(Cl)(Cl)[Cl:22]>O>[CH2:1]([N:3]1[C:7]2=[N:8][C:9]3[C:10]([C:11]([Cl:22])=[C:6]2[CH:5]=[N:4]1)=[CH:14][C:15]([S:18][CH3:19])=[CH:16][CH:17]=3)[CH3:2]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 21217703N-(1-ethylpyrazol-5-yl)-5-(methylthio)anthranilic acid

Product 1

HCID 212177171-ethyl-4-chloro-6-(methylthio)-1H-pyrazolo[3,4-b]quinoline

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of N-(1-ethylpyrazol-5-yl)-5-(methylthio) anthranilic acid (4.5 g) and POCl3 (20 mL) was refluxed overnight. The reaction mixture was poured into water, then ice was added. The mixture was extracted with CH2Cl2 and then the CH2Cl2 layer was evaporated. The residue was purified by column chromatography on silica gel eluting with 50% ethyl acetate/hexane to afford 2.4 g of 1-ethyl-4-chloro-6-(methylthio)-1H-pyrazolo[3,4-b]quinoline, m.p. 120°-121° C.

Workup

  1. temperaturewas refluxed overnight
  2. additionice was added
  3. extractionThe mixture was extracted with CH2Cl2
  4. customthe CH2Cl2 layer was evaporated
  5. customThe residue was purified by column chromatography on silica gel eluting with 50% ethyl acetate/hexane

Sources & evidence

ORD record
ord-0a1660df785c4f4eb149a954ccb2ee9a
Source dataset
uspto-grants-1996_01
Patent number
US05488055

Reaction notes

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