HCID 13273325, compound → HCID 20468454, compound

Participants

Reaction Steps

2-Difluoromethyl-2-(2-phthalimidoethyl)-propanedioic acid, bis tert.-butyl ester prepared as in Step B (0.610 g, 1.40 mM) is dissolved in trifluoroacetic acid (8 ml) at room temperature. After stirring for 1.5 hour at room temperature, the solvent is evaporated in vacuo yielding a white solid. The crude disubstituted malonic acid is dissolved in glacial acetic acid (20 ml) and the mixture is heated at 100° C. for 15 hours. The solvent is evaporated in vacuo yielding a yellowish oil. Crystallization in ether affords the required acid as a white solid (0.240 g, yield 60%). NMR (CDCl3 +CF3CO2H) 2.00-2.43 (m, 2H); 2.57-3.40 (m, 1H); 3.90 (t, JHH =7 Hz, 2H); 6.03 (td, JHF =55 Hz, JHH =4 Hz, 1H); 7.58-7.95 (m, 4H).

Provenance & Evidence