Phosphorus oxychloride → 3-Chloro-2-(2,4-dichloro-6-fluorobenzothiazol-7-yl)-4,5,6,7-tetrahydro-2H-indazole

HRID 21730Notes

Reaction equation

HRID 21730 reaction equation
[Cl:1][C:2]1[S:3][C:4]2[C:10]([N:11]3[C:19](=O)[C:18]4[CH2:17][CH2:16][CH2:15][CH2:14][C:13]=4[NH:12]3)=[C:9]([F:21])[CH:8]=[C:7]([Cl:22])[C:5]=2[N:6]=1.P(Cl)(Cl)([Cl:25])=O>>[Cl:25][C:19]1[N:11]([C:10]2[C:4]3[S:3][C:2]([Cl:1])=[N:6][C:5]=3[C:7]([Cl:22])=[CH:8][C:9]=2[F:21])[N:12]=[C:13]2[C:18]=1[CH2:17][CH2:16][CH2:15][CH2:14]2

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 199334592-(2,4-Dichloro-6-fluorobenzothiazol-7-yl)1,3,4,5,6,7-hexahydro-2H-indazol-3-one

Product 1

HCID 199334603-Chloro-2-(2,4-dichloro-6-fluorobenzothiazol-7-yl)-4,5,6,7-tetrahydro-2H-indazole

Procedure

0.2 g 2-(2,4-Dichloro-6-fluorobenzothiazol-7-yl)1,3,4,5,6,7-hexahydro-2H-indazol-3-one was treated with 2 ml phosphorus oxychloride and the mixture stirred for one hour under reflux. After cooling, it was poured into ice-water, extracted with ethyl acetate and the organic phase washed with sodium hydrogen carbonate and water. It was dried over magnesium sulfate and concentrated. The residue was purified by column chromatography. Yield: 0.07 g=32% of theory m.p.: 161°-163° C.

Workup

  1. temperatureunder reflux
  2. temperatureAfter cooling
  3. extractionextracted with ethyl acetate
  4. washthe organic phase washed with sodium hydrogen carbonate and water
  5. dry with materialIt was dried over magnesium sulfate
  6. concentrationconcentrated
  7. customThe residue was purified by column chromatography

Sources & evidence

ORD record
ord-ecab1ddb575c4a79813f70eaa9956a8a
Source dataset
uspto-grants-1995_06
Patent number
US05424443

Reaction notes

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