Formaldehyde → HCID 53312154, compound

Participants

Reaction Steps

(S)-5-Biphenyl-4-ylmethyl-3-isobutyryl-1-((E)-styryl)-pyrrolidin-2-one (4a, R1=t-butoxycarbonyl, R4=isopropyl) (2.5 g, 6.2 mmol) is dissolved in 10 mL of anhydrous tetrahydrofuran, add iPr2NEt (1.1 g, 8.2 mmol), anhydrous LiCl (140 mg, 3.2 mmol) and molecular sieves (0.5 g), the mixture is refluxed under nitrogen atmosphere for 30 min, then add paraformaldehyde (230 mg, 7.6 mmol) in one portion, reflux for 2 h, cool to room temperature, add 50 mL of toluene, filter, the filtration is washed with 10% HCl(aq), saturated Na2CO3 and brine, dry over anhydrous NaSO4, evaporate under vacuum, the residue is purified by column chromatography to obtain (R)-5-Biphenyl-4-ylmethyl-3-methylene-1-((E)-styryl)-pyrrolidin-2-one (1a, R1=styryl). Stepectroscopic data as Example 23, Method 1.

Provenance & Evidence