Sulfuric Acid → HCID 118415298, compound

Participants

Reaction Steps

To a solution of (S)-2-(benzyl(methyl)amino)-2-cyclopentylacetaldehyde (7.9 g, 34 mmol, 1.0 eq) in MeOH (200 mL) was added concentrated H2SO4 (12.5 g, 127 mmol, 3.7 eq) drop-wise at 0° C. The reaction mixture was stirred for 10 min, then trimethylorthoformate was added (33 g, 311 mmol, 9.0 eq.) at 0° C. The reaction mixture was stirred at room temperature for 1 hour, and then heated to reflux for overnight. After cooled, the solvent was evaporated under reduced pressure, and the obtained residue was poured into sat NaHCO3 (300 mL, aq), extracted with ethyl acetate (300 mL). The organic layer was washed with brine, dried over sodium sulphate and evaporated to give a residue, which was purified by column chromatography on silica to yield the product 6 (8.6 g, 90% for two steps) as a light color oil.

Provenance & Evidence