Benzenesulfonyl chloride → 1H-Pyrazole-5-carboxylic acid, 1-(3-chloro-2-pyridinyl)-4,5-dihydro-3-[(phenylsulfonyl)oxy]-, ethyl ester

HRID 646643Notes

Reaction equation

HRID 646643 reaction equation
C(N(CC)CC)C.[Cl:8][C:9]1[C:10]([N:15]2[CH:19]([C:20]([O:22][CH2:23][CH3:24])=[O:21])[CH2:18][C:17](=[O:25])[NH:16]2)=[N:11][CH:12]=[CH:13][CH:14]=1.[C:26]1([S:32](Cl)(=[O:34])=[O:33])[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1>ClCCl>[Cl:8][C:9]1[C:10]([N:15]2[CH:19]([C:20]([O:22][CH2:23][CH3:24])=[O:21])[CH2:18][C:17]([O:25][S:32]([C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)(=[O:34])=[O:33])=[N:16]2)=[N:11][CH:12]=[CH:13][CH:14]=1

Participants

5

Reactant 3

HCID 7369Benzenesulfonyl chloride2×HCID 8471Triethylamine2×HCID 22280352Ethyl 2-(3-Chloro-2-pyridinyl)-5-oxo-3-pyrazolidinecarboxylate

Product 1

HCID 866008331H-Pyrazole-5-carboxylic acid, 1-(3-chloro-2-pyridinyl)-4,5-dihydro-3-[(phenylsulfonyl)oxy]-, ethyl esterYield 94%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Triethylamine (1.85 g, 18.5 mmol) was added dropwise over 1 h to a mixture of ethyl 2-(3-chloro-2-pyridinyl)-5-oxo-3-pyrazolidinecarboxylate (i.e. the product of Example 1, Step A) (5.0 g, 18.5 mmol) and benzenesulfonyl chloride (3.27 g, 18.5 mmol) in dichloromethane (20 mL) at 0° C. The temperature was not allowed to exceed 1° C. After stirring the reaction mixture for an additional 2 h, a further portion of benzenesulfonyl chloride (0.5 g, 1.85 mmol) was added. Then a further portion of triethylamine (0.187 g, 1.85 mmol) was added dropwise to the mixture. After stirring for 0.5 h more, the mixture was partitioned between water (100 mL) and dichloromethane (100 mL). The organic layer was dried (MgSO4) and evaporated to provide the title product as an orange solid (7.18 g, 94% yield). Product recrystallized from ethyl acetate/hexanes melted at 84-85° C.

Workup

  1. customto exceed 1° C
  2. stirringAfter stirring for 0.5 h more
  3. customthe mixture was partitioned between water (100 mL) and dichloromethane (100 mL)
  4. dry with materialThe organic layer was dried (MgSO4)
  5. customevaporated

Sources & evidence

ORD record
ord-33a8aca28a6c455c99f2c10c6e96a780
Source dataset
uspto-grants-2010_04
Patent number
US07705160B2

Reaction notes

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