Cornforth reagent → 5-Acetyl-4-tert-butyl-3-(4-methylphenyl)sulfonyloxypyrazole

HRID 985431Notes

Reaction equation

HRID 985431 reaction equation
[C:1]([C:5]1[C:6]([O:13][S:14]([C:17]2[CH:22]=[CH:21][C:20]([CH3:23])=[CH:19][CH:18]=2)(=[O:16])=[O:15])=[N:7][NH:8][C:9]=1[CH:10]([OH:12])[CH3:11])([CH3:4])([CH3:3])[CH3:2].C1C=C[NH+]=CC=1.C1C=C[NH+]=CC=1.[O-][Cr](O[Cr]([O-])(=O)=O)(=O)=O>ClCCl>[C:10]([C:9]1[NH:8][N:7]=[C:6]([O:13][S:14]([C:17]2[CH:22]=[CH:21][C:20]([CH3:23])=[CH:19][CH:18]=2)(=[O:16])=[O:15])[C:5]=1[C:1]([CH3:4])([CH3:3])[CH3:2])(=[O:12])[CH3:11]

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 225068894-Tert-butyl-5-(1-hydroxyethyl)-3-(4-methylphenyl)sulfonyloxypyrazole

Product 1

HCID 225068935-Acetyl-4-tert-butyl-3-(4-methylphenyl)sulfonyloxypyrazoleYield 71.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-tert-Butyl-5-(1-hydroxyethyl)-3-(4-methylphenyl)sulfonyloxypyrazole (3.8 g, 11.3 mmol) was dissolved in dichloromethane (100 ml) and PDC (4.26 g, 11.3 mmol) was added After stirring at ambient temperature for 2 h, the reaction mixture was poured directly onto a silica gel column and eluted with dichloromethane then 20% ethyl acetate/dichloromethane to give the required product (2.71 g) as a white solid. 1H NMR (360 MHz, CDCl3) δ 1.26 (9H, s), 2.46 (3H, s), 2.56 (3H, s), 7.36 (2H, d, J=8.2 Hz), 7.82 (2H, d, J=8.2 Hz), 10.70 (1H, br s); MS (ES+) m/e 337 [MH]+.

Workup

  1. additionthe reaction mixture was poured directly onto a silica gel column
  2. washeluted with dichloromethane

Sources & evidence

ORD record
ord-63b80a74f8c84cdaad02fa24701c2f14
Source dataset
uspto-grants-2005_03
Patent number
US06872720B2

Reaction notes

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