4-(methoxymethyl)-1H-Pyrazole synthesis

Yield:37599-34-1 38%

Reaction Conditions:

Stage #1: trityl-4-methoxymethylpyrazolewith trifluoroacetic acid in methanol;dichloromethane at 75 - 80;
Stage #2: with sodium hydrogencarbonate in water;ethyl acetate;

Steps:

2.b

CF₃COOH was added to a solution of l-trityl-4- methoxymethylpyrazole in CH₂Cl₂/MeOH (1 :1). The mixture was heated at 75-80 ⁰C overnight. After cooling to room temperature, the solvent was removed under the vacuum and the residue was applied on the top of a silica-gel column and eluted with methanol/ethyl acetate (5:95). The solvent from the collected fractions was removed under vacuum, and the residue redissolved in ethyl acetate. The title compound was recovered as a slightly yellow oil, after washing the organic phase with a saturated solution of NaHCO₃ and distilled water, followed by removal of the solvent and prolonged drying under vacuum. Yield: 38 % (60 mg, 0.54 mmol). ¹H NMR (CDCl₃, δ ppm): 7.57 (2H, s, H-3/5 (pz)), 4.38 (2H, s, CH₂), 3.34 (3H, s, CH₃).

References:

WO2008/61792,2008,A2 Location in patent:Page/Page column 16