2-Benzyloxymethyl-2H-pyrazole-3-carbaldehyde → 1-Benzyloxymethyl-5-vinyl-1H-pyrazole

HRID 660491Notes

Reaction equation

HRID 660491 reaction equation
[Li][CH3:2].[CH2:3]([O:10][CH2:11][N:12]1[C:16]([CH:17]=O)=[CH:15][CH:14]=[N:13]1)[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[CH2:3]([O:10][CH2:11][N:12]1[C:16]([CH:17]=[CH2:2])=[CH:15][CH:14]=[N:13]1)[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1

Participants

5

Reactant 2

HCID 866325702-Benzyloxymethyl-2H-pyrazole-3-carbaldehydeHCID 178418348HCID 178418348, compound

Product 1

HCID 688389771-Benzyloxymethyl-5-vinyl-1H-pyrazole

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of methyltriphenylphosphoniumbromide (7.85 g, 22.0 mmol) in THF (40 mL) is cooled to 0° C. then MeLi (12.2 mL, 1.6 M in ether) is added dropwise. The mixture is stirred for 1 h then a solution of 2-benzyloxymethyl-2H-pyrazole-3-carbaldehyde (3.4 g, 15.7 mmol) in THF (15 mL) is added dropwise. The reaction is stirred for an hour at 0° C., then warmed to RT over 1 h. The mixture is partitioned between aqueous NH4Cl and EtOAc and the organic layer is concentrated. Chromatography (10-15% EtOAc/hexane) affords the title compound as a yellow oil: (M+1)+=215.

Workup

  1. stirringThe reaction is stirred for an hour at 0° C.
  2. customThe mixture is partitioned between aqueous NH4Cl and EtOAc
  3. concentrationthe organic layer is concentrated

Sources & evidence

ORD record
ord-98318e0aeced46be87c79127b2320e92
Source dataset
uspto-grants-2011_12
Patent number
US08084448B2

Reaction notes

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