Benzyl chloroformate → (+/-)-4,5-Dihydro-1-(benzyloxycarbonyl)-3-(2-thienyl)-1H-pyrazole-5-carboxylic acid

HRID 126994Notes

Reaction equation

HRID 126994 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]1[CH2:10][CH:9]([C:11]([OH:13])=[O:12])[NH:8][N:7]=1.C(=O)([O-])[O-].[K+].[K+].Cl[C:21]([O:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)=[O:22]>O.CC(C)=O>[CH2:24]([O:23][C:21]([N:8]1[CH:9]([C:11]([OH:13])=[O:12])[CH2:10][C:6]([C:2]2[S:1][CH:5]=[CH:4][CH:3]=2)=[N:7]1)=[O:22])[C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1

Participants

6

Reactant 3

HCID 10387Benzyl chloroformateHCID 11430Potassium CarbonateHCID 20288723(+/-)-4,5-Dihydro-3-(2-thienyl)-1H-pyrazole-5-carboxylic acid

Product 1

HCID 20288724(+/-)-4,5-Dihydro-1-(benzyloxycarbonyl)-3-(2-thienyl)-1H-pyrazole-5-carboxylic acid

Reagents, catalysts & solvents 2

HCID 180AcetoneSolvent2×HCID 962WaterSolvent2×

Procedure

To a stirred mixture of 9.8 g of (±)-4,5-dihydro-3-(2-thienyl)-1H-pyrazole-5-carboxylic acid (see example 2B) and 13.8 g of potassium carbonate in 80 ml of water and 40 ml of acetone there is added slowly 9.3 g of benzyl chloroformate dissolved in 50 ml of acetone, maintaining the temperature of the mixture at 10°-15° C. with an ice bath. After stirring at room temperature for 2 hours, the mixture is diluted with an equal volume of water and washed twice with ether. The aqueous layer containing some solids, is adjusted to pH 3.0 with 6 N HCl and cooled and filtered to obtain the title compound.

Workup

  1. temperaturemaintaining the temperature of the mixture at 10°-15° C. with an ice bath
  2. washwashed twice with ether
  3. additionThe aqueous layer containing some solids
  4. temperaturecooled
  5. filtrationfiltered

Sources & evidence

ORD record
ord-e2b9b2ef1e68470fa819362e9bb64a13
Source dataset
uspto-grants-1981_03
Patent number
US04254267

Reaction notes

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