Nitrogen → 2-(methyl(trityl)amino)-1-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol-5-yl)ethanol

Participants

Reaction Conditions

Reaction Steps

A solution of 1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazole (Heterocycles (1992), 34(2), 303-14)(0.80 g, 4.03 mmol) in 50 mL of THF/ether (3/2) was cooled to −78° C. and treated with 2.5M solution of n-BuLi (1.8 mL, 4.43 mmol) dropwise under N2 atmosphere. The resulting mixture was stirred for 30 min. [Methyl(trityl)amino]acetaldehyde (1.27 g, 4.04 mmol) in 5 mL of the THF/ether solution was added to reaction mixture and stirred for 1 h at −79° C. and warmed up to room temperature. The reaction was quenched by adding NH4Cl (sat. aq.) and water dropwise and the resulting suspension was extrcted into EtOAc (2×100 mL). The organic phase was washed with water (100 mL) and brine (50 mL), dried over Na2SO4, filtered and concentrated in vacuo. The residue was chromatographed on a Flash 40M silica gel (90 g, 32-63 μm) cartridge, eluting with 20% EtOAc in n-heptane, and those fractions with Rf=0.3 by TLC(EtOAc/hexane, 3/7) were combined and concentrated in vacuo to give 0.7 g of the product as a white solid.

Provenance & Evidence