Potassium Carbonate → 1-[3-(Tert-butyldimethylsilyloxy)propoxy]-5-methylpyrazole-3-carboxylic acid ethyl ester

HRID 1869575Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[C:9]([CH3:11])[NH:8][N:7]=1)=[O:5])[CH3:2].C(=O)([O-])[O-:13].[K+].[K+].[Si:18]([O:25][CH2:26][CH2:27][CH2:28]Br)([C:21]([CH3:24])([CH3:23])[CH3:22])([CH3:20])[CH3:19]>CN(C=O)C>[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[C:9]([CH3:11])[N:8]([O:13][CH2:28][CH2:27][CH2:26][O:25][Si:18]([C:21]([CH3:24])([CH3:23])[CH3:22])([CH3:20])[CH3:19])[N:7]=1)=[O:5])[CH3:2]

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of 1.96 g of 5-methylpyrazole-3-carboxylic acid ethyl ester in 40 ml of DMF, 2.64 g of potassium carbonate and 3.53 ml of 3-(tert-butyldimethylsilyloxy)propylbromide were added, and the mixture was stirred at 50° C. for 18 hours. The solvent was evaporated, EtOAc was added to the residue, and the organic layer was washed with water and brine and dried over sodium sulfate. After the evaporation of the solvent, the obtained residue was purified by silica gel column chromatography (eluent: hexane-EtOAc=15:1˜5:1) to obtain 1.39 g of 1-[3-(tert-butyldimethylsilyloxy)propoxyl]-5-methylpyrazole-3-carboxylic acid ethyl ester.

Workup

customThe solvent was evaporated
additionEtOAc was added to the residue
washthe organic layer was washed with water and brine
dry with materialdried over sodium sulfate
customAfter the evaporation of the solvent
customthe obtained residue was purified by silica gel column chromatography (eluent: hexane-EtOAc=15:1˜5:1)

Sources & evidence

ORD record: ord-ceaab2cd0bca451b956234e5da7dcd72
Source dataset: uspto-grants-2009_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07638536B2

Reaction notes

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