Diisopropylethylamine → HCID 178429007, compound

Participants

Reaction Conditions

Reaction Steps

To a solution N-(tert-butoxycarbonyl)-2,6-dimethyl-L-tyrosyl-N-[(2S)-2-amino-3-phenylpropyl]-D-alaninamide (330 mg, 0.64 mmol) from preparation 33 in THF (5 mL) was added N,N′-Bis(benzyloxycarbonyl)-1H-pyrazole-1-carboxamidine (268 mg, 0.71 mmol) and N,N-diisopropylethylamine (173 uL, 0.97 mmol). The reaction was stirred for 2 hours at 60° C. and then quenched by the addition of water (5 mL). The mixture was extracted with ethyl acetate (10 mL), the extract was dried over sodium sulphate and concentrated under reduced pressure. The residue was purified by column chromatography (silica, 25% ethyl acetate in heptane as eluent increasing to 33%) to afford the title compound as a colourless oil in 81% yield, 430 mg. 1H NMR (400 MHz, MeOH-d4) δ : 1.05 (d, 3H), 1.28 (s, 9H), 2.22 (s, 6H), 2.73-3.11 (m, 4H), 3.41-3.52 (m, 1H), 3.95-4.23 (m, 2H), 4.38-4.59 (m, 2H), 4.98-5.28 (m, 4H), 6.45 (s, 2H), 7.09-7.46 (m, 15H). LRMS APCI m/z 823 [MH]+

Provenance & Evidence