Triethylamine → Ethyl 1-(2-t-butyldimethylsilyloxyethyl)-5-methylpyrazole-3-carboxylate

HRID 976999Notes

Reaction equation

HRID 976999 reaction equation
[OH:1][CH2:2][CH2:3][N:4]1[C:8]([CH3:9])=[CH:7][C:6]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[N:5]1.C(N(CC)CC)C.[Si:22](Cl)([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23]>ClCCl>[Si:22]([O:1][CH2:2][CH2:3][N:4]1[C:8]([CH3:9])=[CH:7][C:6]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[N:5]1)([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 28928tert-Butyldimethylsilyl chlorideHCID 22145424Ethyl 1-(2-hydroxyethyl)-5-methylpyrazole-3-carboxylate

Product 1

HCID 22145416Ethyl 1-(2-t-butyldimethylsilyloxyethyl)-5-methylpyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Ethyl 1-(2-hydroxyethyl)-5-methylpyrazole-3-carboxylate (9.39 g, 47.4 mM) in dichloromethane (150 ml) was cooled to below 0° C. and treated with triethylamine (7.19 ml, 52 mM) followed by t-butyldimethylsilyl chloride (7.85 g, 52 mM). The mixture was stirred at room temperature for 3 days. The reaction mixture was washed with brine, dried (MgSO4) and evaporated. Purification on silica geleluting with 50% ethyl acetate in hexane gave the title compound as a pale yellow solid in quantitative yield; νmax (film) 1719, 1472 and 1388 cm-1 ; δH (CDCl3) -0.08 (6H, s), 0.81 (9H, s), 1.38 (3H, t, J7 Hz), 2.33 (3H, s), 3.98 (2H, t, J5 Hz), 4.21 (2H, t, J5 Hz), 4.39 (2H, q, J7 Hz), and 6.53 (1H, s); NH3DCI m/e 313 (100%).

Workup

  1. washThe reaction mixture was washed with brine
  2. dry with materialdried (MgSO4)
  3. customevaporated
  4. customPurification on silica geleluting with 50% ethyl acetate in hexane

Sources & evidence

ORD record
ord-015092eaa2ce43c686b1172857c40c2c
Source dataset
uspto-grants-1997_03
Patent number
US05612477

Reaction notes

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