Formaldehyde → HCID 53312154, compound

Participants

Reaction Steps

(S)-3-Benzoyl-5-biphenyl-4-ylmethyl-1-((E)-styryl)-pyrrolidin-2-one (4a, R1=styryl, R4=phenyl) (10.0 g, 21.9 mmol) is dissolved in 50 mL of anhydrous tetrahydrofuran, add iPr2NEt (3.7 g, 28.5 mmol) anhydrous Lithium chloride (490 mg, 11.0 mmol) and molecular sieves (2.0 g), refluxed for 30 min under nitrogen atmosphere, then add paraformaldehyde (790 mg, 26.3 mmol), reflux for 2 h under nitrogen atmosphere. The reaction mixture is cooled to room temperature, add 100 mL of toluene, filter to remove the molecular sieves, the filtration is washed with 5% HCl(aq) (50 mL*2), saturated Na2CO3 and brine, dry over anhydrous Na2SO4 and concentrate under vacuum to obtain (R)-5-Biphenyl-4-ylmethyl-3-methylene-1-((E)-styryl)-pyrrolidin-2-one (1a, R1=styryl), which is direct used in next step. Spectroscopic data as Example 23, Method 1.

Provenance & Evidence