Benzyl N3,N7,N12,N16-tetra(t-butoxycarbonyl)-3,7,12,16-tetraazahexadecanoate → N3,N7,N12,N16-Tetra(t-butoxycarbonyl)-3,7,12,16-tetraazahexadecanoic acid

Participants

Reaction Steps

A solution of 30 (1.56 g, 2.08 mmol) in MeOH (21 mL) was degassed with argon for 10 min followed by the addition of 10% Pd/C (400 mg). The mixture was then stirred under an atmosphere of hydrogen for 3 h. The mixture was filtered through glassfiber filter paper and the filtrate was concentrated under reduced pressure to give crude 31 (1.37 g, 100%) as a colourless liquid that was used without purification: 1H NMR (400 MHz, acetone-d6): δ 1.40 (bs, 9H), 1.44-1.46 (m, 27H), 1.52 (bs, 4H), 1.66-1.83 (m, 4H), 3.06 (bt, J=5.6, 2H), 3.22-3.32 (m, 10H), 3.94 (s, ½ of 2H, rotomer A), 3.97 (s, ½ of 2H, rotamer B), 5.98 (bs, 1H).

Provenance & Evidence