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

HRID 2196485Notes

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)propoxy]-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-899736e0661e457288d24e20882c414b
Source dataset: uspto-grants-2012_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08338429B2

Reaction notes

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