Triphenylphosphine → 1-(4-tert-butoxyethoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester

HRID 1748560Notes

Reaction equation

HRID 1748560 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([C:12]2[CH:17]=[CH:16][C:15]([OH:18])=[CH:14][CH:13]=2)[C:10]=1[CH3:11])=[O:5])[CH3:2].[C:19]([O:23][CH2:24][CH2:25]O)([CH3:22])([CH3:21])[CH3:20].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(OC(N=NC(OC(C)C)=O)=O)(C)C>O1CCCC1.C1(C)C=CC=CC=1.O>[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([C:12]2[CH:13]=[CH:14][C:15]([O:18][CH2:25][CH2:24][O:23][C:19]([CH3:22])([CH3:21])[CH3:20])=[CH:16][CH:17]=2)[C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

8

Reactant 4

HCID 11776TriphenylphosphineHCID 242322-(Tert-butoxy)ethan-1-olHCID 75555Diisopropyl diazene-1,2-dicarboxylateHCID 866924241-(4-hydroxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester

Product 1

HCID 897349361-(4-tert-butoxyethoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl esterYield 123.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 1-(4-Hydroxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (500 mg) in Reference Example 39 (2), 2-tert-butoxyethanol (480 mg) and triphenylphosphine (1.06 g) in tetrahydrofuran (20 ml) was added dropwise a solution of 40% azodicarboxylic acid diisopropylester in toluene (2.14 ml) under ice-cooling, and then stirred at room temperature overnight. After completion of the reaction, water was added thereto, extracted with ethyl acetate, the organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated in vacuo. The obtained residue was purified with silica gel chromatography (n-hexane/ethyl acetate) to give 1-(4-tert-butoxyethoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (870 mg) as a pale yellow oil.

Workup

  1. temperaturecooling
  2. additionwas added
  3. extractionextracted with ethyl acetate
  4. dry with materialthe organic layer was dried over anhydrous sodium sulfate
  5. customthe solvent was evaporated in vacuo
  6. customThe obtained residue was purified with silica gel chromatography (n-hexane/ethyl acetate)

Sources & evidence

ORD record
ord-013471679a6f441082657b4f815af7a3
Source dataset
uspto-grants-2015_10
Patent number
US09150555B2

Reaction notes

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