4-Toluenesulfonyl chloride → toluene-4-sulfonic acid 5-[(S)-l-hydroxyethyl]-1H-pyrazol-3-yl ester

HRID 985437Notes

Reaction equation

HRID 985437 reaction equation
[OH:1][C:2]1[CH:6]=[C:5]([C@@H:7]([OH:9])[CH3:8])[NH:4][N:3]=1.[C:10]1([CH3:20])[CH:15]=[CH:14][C:13]([S:16](Cl)(=[O:18])=[O:17])=[CH:12][CH:11]=1.C(N(CC)CC)C>ClCCl>[OH:9][C@H:7]([C:5]1[NH:4][N:3]=[C:2]([O:1][S:16]([C:13]2[CH:14]=[CH:15][C:10]([CH3:20])=[CH:11][CH:12]=2)(=[O:18])=[O:17])[CH:6]=1)[CH3:8]

Participants

5

Reactant 3

HCID 73974-Toluenesulfonyl chlorideHCID 8471TriethylamineHCID 178462232HCID 178462232, compound

Product 1

HCID 87418248toluene-4-sulfonic acid 5-[(S)-l-hydroxyethyl]-1H-pyrazol-3-yl esterYield 79%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of (S)-3-hydroxy-5-(1-hydroxyethyl)-1H-pyrazole (0.5056 g, 3.95 mmol) in anhydrous dichloromethane (20 ml) under nitrogen was added p-toluenesulfonyl chloride (0.8276 g, 4.34 mmol) then, dropwise, triethylamine (0.66 ml, 4.74 mmol). The mixture was stirred at room temperature for 3 h, then washed with saturated NaCl (15 ml). The aqueous layer was further extracted with dichloromethane (2×25 ml) and the combined organic extracts were dried (NaSO4) and evaporated in vacuo. The residue was purified by flash chromatography (silica gel, 5% MeOH/CH2Cl2) to give 0.8770 g (79%) of the title compound as an orange oil: 1H NMR (400 MHz, DMSO-d6) δ 1.31 (3H, d, J=6.5 Hz), 2.42 (3H, s), 4.67 (1H, m), 5.40 (1H, d, J=5.1 Hz), 5.79 (1H, d, J=2.1 Hz), 7.47 (2H, d, J=8.1 Hz), 7.77 (2H, d, J=8.4 Hz), 12.48 (1H, s); MS (ES+) m/e 283 [M+H]+, 265 [M−OH]+.

Workup

  1. washwashed with saturated NaCl (15 ml)
  2. extractionThe aqueous layer was further extracted with dichloromethane (2×25 ml)
  3. dry with materialthe combined organic extracts were dried (NaSO4)
  4. customevaporated in vacuo
  5. customThe residue was purified by flash chromatography (silica gel, 5% MeOH/CH2Cl2)

Sources & evidence

ORD record
ord-c7b47a150ecf4e978ca02ed9ed4009d8
Source dataset
uspto-grants-2005_03
Patent number
US06872720B2

Reaction notes

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