p-Toluenesulfonic acid → 3-Chloro-5-(1,3-dioxan-2-yl)-1H-indazole

HRID 1038398Notes

Reaction equation

HRID 1038398 reaction equation
[Cl:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([CH:11]=[O:12])[CH:9]=2)[NH:4][N:3]=1.[CH2:13](O)[CH2:14][CH2:15][OH:16].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[Cl:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([CH:11]3[O:16][CH2:15][CH2:14][CH2:13][O:12]3)[CH:9]=2)[NH:4][N:3]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 104421,3-PropanediolHCID 1785193763-Chloro-1H-indazole-5-carboxaldehyde

Product 1

HCID 1784784203-Chloro-5-(1,3-dioxan-2-yl)-1H-indazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

2.2 g (12.2 mmol) 3-chloro-1H-indazole-5-carbaldehyde (Example 43A), 4.64 g (60.9 mmol) propane-1,3-diol and a trace amount of p-toluene sulfonic acid in toluene (60 ml) were heated to reflux for 12 h using a Dean-Stark trap. After cooling, the mixture was concentrated under reduced pressure. The residue was dissolved in ethyl acetate and washed with water. The organic layer was dried with sodium sulfate, filtered and evaporated to dryness. The remaining solid (2.76 g, 91% of th.) was used in the next step without further purification.

Workup

  1. temperatureto reflux for 12 h
  2. temperatureAfter cooling
  3. concentrationthe mixture was concentrated under reduced pressure
  4. dissolutionThe residue was dissolved in ethyl acetate
  5. washwashed with water
  6. dry with materialThe organic layer was dried with sodium sulfate
  7. filtrationfiltered
  8. customevaporated to dryness
  9. customThe remaining solid (2.76 g, 91% of th.) was used in the next step without further purification

Sources & evidence

ORD record
ord-a8a662aac0e74e01b05d2ae9e9cc8ccc
Source dataset
uspto-grants-2013_10
Patent number
US08551989B2

Reaction notes

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