Formaldehyde → HCID 53312154, compound

Participants

Reaction Steps

Biphenyl-4-ylmethyl-2-oxo-pyrrolidine-1,3-dicarboxylic acid 1-tert-butyl ester (4a, R1=t-butoxycarbonyl, R4=hydroxyl) (3.95 g, 10.0 mmol) is dissolved in 10 mL of methanol, add paraformaldehyde (0.60 g, 20.0 mmol) and morpholine (1.05 g, 12.0 mmol), the mixture is heated to refluxed for 2 h under nitrogen atmosphere, cool to room temperature, evaporate the solvent under vacuum, the residue is dissolved in 50 mL of ethyl acetate, ish with 1% HCl(aq), 10% sodium hydrogen carbonate(aq) and brine, dry over anhydrous sodium sulfate and concentrate under vacuum to obtain (R)-5-Biphenyl-4-ylmethyl-3-methylene-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (1a, R1=t-butoxycarbonyl). 1HNMR (400 MHz, CDCl3): 1.62 (s, 9H, (CH3) 3), 2.56 (m, 1H, 3-CHH), 2.60 (m, 1H, 3CHH), 2.70 (d, 1H, 5-CHH), 3.26 (d, 1H, 5-CHH), 4.43 (m, 1H, 4-CH), 5.45 (d, 1H, C═CHH), 6.17 (d, 1H, C═CHH), 7.20˜7.60 (9H, m, aromatic); m/z (+ESI) 381 ([MNa]+, 7%), 364 ([MH]+, 12), 308(100), 264 (10).

Provenance & Evidence