Trifluoroacetic acid → HCID 86671347, compound

Participants

Reaction Steps

A 50% (v/v) solution of TFA in CH2Cl2 (350 mL) was added to N-tert-butoxycarbonyl α,α-dimethylglycyl L-valine methyl ester (5) (33.50 g, 0.1059 mol) at room temperature and the reaction mixture stirred for 2 hours. The solvent and bulk of excess TFA were removed under reduced pressure. The residue was washed with Et2O (3×200 mL) and dried under reduced pressure affording a clear oil. Dichloromethane (3×200 mL) was added and evaporated under reduced pressure affording a sticky white solid (28.51 g, 82%); δH (300 MHz; d6-DMSO) 8.42 (1H, d, J 8, NH), 8.26 (3H, br s, NH3+), 4.17 (1H, dd, J 8 and 8, CαH(Val)), 3.64 (3H, s, OCH3), 2.16-2.05 (1H, m, CH(CH3)2), 1.52 (3H, s, CH3(Aib)), 1.50 (3H, s, CH3(Aib)), 0.91 (3H, d, J 6, CH3(Val)), 0.88 (3H, d, J 6, CH3(Val)); δC (75 MHz; d6-DMSO) 172.0, 171.6, 158.1 (q, JcF 32), 116.9 (q, JCF 297), 58.3, 56.5, 51.7, 29.5, 23.2, 23.1, 19.0, 18.6; m/z (ESI) 217.1556 (M+; C10H21N2O3 requires 217.1552)

Provenance & Evidence