Diisopropylethylamine → HCID 66868028, compound

Participants

Reaction Steps

To a stirred solution of (S)-3-Amino-4-hydroxy-butyric acid tert-butyl ester (486 mg) and (1R,3S,4S)-2-Aza-bicyclo[2.2.l]heptane-2,3-dicarboxylic acid 2 benzyl ester (prepared as described in Tararov etal, Tett. Asymm. 2002, 13, 25-28) (767 mg) in THF (18 ml) was added 2-hydroxybenzotriazole hydrate (452 mg), DMAP (426 mg), diisopropylethylamine (631□1) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC, 641 mg). The resulting mixture was stirred at ambient temperature for 18 hours then diluted with ethyl acetate. The mixture was then washed with water, saturated aqueous sodium bicarbonate solution and brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (60% ethyl acetate/petrol) to afford the sub-title compound as a colorless oil (1.1 g, 91%); 1H NMR (400 MHz, d-6 DMSO) δ 1.13-1.25 (1H, m), 1.30-1.48 (9H, m), 1.49-1.88 (6H, m), 2.20-2.52 (2H, m), 3.09-3.34 (2H, m), 3.64 (1H, d), 4.00-4.16 (2H, brm), 4.80 (1H, m), 4.90-5.15 (2H, m), 7.21-7.41 (5H, m), 7.50-7.75 (1H, m); MS ES (+) 433.37.

Provenance & Evidence