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

HRID 2057109Notes

Reaction equation

HRID 2057109 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-92134ee2b6654876ad982fc946445c62
Source dataset
uspto-grants-2008_02
Patent number
US07335780B2

Reaction notes

Loading…