1,8-Diazabicyclo(5.4.0)undec-7-ene → HCID 87524929, compound

Participants

Reaction Steps

Nitrophenylethyl ester 18 (1.39 g, 1.22 mol) was deprotected by treatment with 6.6 mmol of DBU in 20 mL of anhydrous DMF for 2 h at 50° C. DMF was evaporated and the residue triturated with methanol. Insoluble material was collected by filtration washed with methanol and dried under vacuum overnight. The solid was re-dissolved in 20 mL of DMF and treated with diisopropylethylamine (1.5 mL, 8.6 mmol) and pentafluorophenyl trifluoroacetate (1.0 mL, 5.8 mmol). After being stirred at room temperature for 2 h DMF was evaporated and the residue triturated with methanol. Precipitated product was collected by filtration, washed with methanol and dried under vacuum to afford 1.41 g (100%) of the desired PFP ester 19 as a yellow solid. 1H NMR (DMSO-d6) δ 12.54 (s, 1H), 11.80 (s, 1H), 11.70 (s, 1H), 8.43 (d, J=9 Hz, 1H), 8.30 (m, 1H), 8.22 (d, J=9 Hz, 1H), 7.558 (s, 1H), 7.5-7.2 (m, 12H), 7.09 (s, 1H), 6.97 (s, 1H), 6.87 (d, J=9 Hz, 4H), 4.6 (m, 4H), 4.11 (t, J=7 Hz, 2H), 3.73 (s, 6H), 3.43 (m, 4H), 3.28 (t, J=8 Hz, 2H), 2.97 (t, J=6 Hz, 2H), 2.37 (t, J=6 Hz, 2H), 1.57 (m, 4H), 1.40 (m, 2H).

Provenance & Evidence