Trifluoroacetic acid → Glycyl glycine methyl ester trifluoroacetate

Participants

Reaction Steps

N-tert-butoxycarbonyl glycyl glycine methyl ester 19 (9.20 g, 37.4 mmol) was dissolved in a 50% (v/v) solution of TFA in CH2Cl2 (120 mL) at room temperature. The reaction mixture was stirred for 1 h 30 min before the solvent and bulk of excess TFA were evaporated. The residue was washed with Et2O (3×50 mL) and CH2Cl2 (50 mL) and dried affording the title compound as a slightly reddish viscous liquid in quantitative yield and with spectral characteristics in accordance with literature data.9; δH (300 MHz; d6-DMSO) 8.91 (1H, t, J 6, NH), 8.20 (3H, br s, NH3+), 3.96 (2H, d, J 6, CαH2(Gly2)), 3.67-3.59 (5H, m, CαH2(Gly1)/OCH3); 13C-NMR (75 MHz, d6-DMSO): δC 169.9, 166.7, 158.7 (q, JCF 33), 116.4 (q, JCF 294), 54.9, 51.8, 40.6; m/z (ESI) 147.0769 (M+; C5H11N2O3 requires 147.0769)

Provenance & Evidence