Ammonium Chloride → 2-(1-methyl-1H-pyrazol-3-yl)-4-(trimethylsilyl)but-3-yn-2-ol

HRID 1398606Notes

Reaction equation

HRID 1398606 reaction equation
I[C:2]1[CH:6]=[CH:5][N:4]([CH3:7])[N:3]=1.C([Mg]Br)C.[CH3:12][Si:13]([CH3:20])([CH3:19])[C:14]#[C:15][C:16](=[O:18])[CH3:17].[Cl-].[NH4+]>C(Cl)Cl.C1COCC1>[CH3:7][N:4]1[CH:5]=[CH:6][C:2]([C:16]([OH:18])([C:15]#[C:14][Si:13]([CH3:20])([CH3:19])[CH3:12])[CH3:17])=[N:3]1

Participants

7

Reactant 4

HCID 25517Ammonium ChlorideHCID 27346644-(Trimethylsilyl)-3-butyn-2-oneHCID 133340573-Iodo-1-methyl-1H-pyrazoleHCID 178418443HCID 178418443, compound

Product 1

HCID 681819652-(1-methyl-1H-pyrazol-3-yl)-4-(trimethylsilyl)but-3-yn-2-ol

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 3-iodo-1-methyl-1H-pyrazole (378 mg, 1.82 mmol) in dry DCM (15 mL) at 0° C. under an atmosphere of nitrogen, was introduced ethylmagnesium bromide (2.0 mL of a 1.0M solution in THF, 2.0 mmol). After 30 minutes at 0° C., the reaction mixture was warmed to RT for 15 minutes, then introduced to a solution of 4-(trimethylsilyl)but-3-yn-2-one (0.37 ml, 2.18 mmol) in dry DCM (5 ml) at 0° C. under an atmosphere of nitrogen. The reaction mixture was warmed to RT for 16 hr. Following addition of saturated aqueous ammonium chloride (5 ml), the reaction mixture was extracted with DCM (3×5 mL extractions). The combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo. Purification of the residue by silica gel flash column chromatography (heptane/EtOAc gradient) furnished the title compound as an orange-brown oil: 1H NMR (500 MHz, CDCl3) delta 0.15 (9H, d, J=3.5 Hz), 1.82 (3H, s), 3.18 (1H, s), 3.86 (3H, s), 6.28 (1H, d, J=2.2 Hz), 7.26 (1H, d, J=2.2 Hz); LC-MS: m/z=+222.95 (M+H)+.

Workup

  1. temperatureThe reaction mixture was warmed to RT for 16 hr
  2. extractionthe reaction mixture was extracted with DCM (3×5 mL extractions)
  3. dry with materialThe combined organic extracts were dried (Na2SO4)
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customPurification of the residue by silica gel flash column chromatography (heptane/EtOAc gradient)

Sources & evidence

ORD record
ord-d8579eb63ebf494babb476e7f50a4505
Source dataset
uspto-grants-2014_12
Patent number
US08901313B2

Reaction notes

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