Synthesis of Benzyl-Protected t-TUCB Derivative

Example 7

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t-TUCB (245 mg, 0.56 mmol), benzyl alcohol (200 uL, 1.93 mmol), 1-ethyl-3-dimethylaminopropyl)carbodiimide (EDCI, 148 mg, 0.95 mmol), 4-dimethylaminopyridine (DMAP, 5 mg, 0.04 mmol) and trimethylamine (Et₃N, 63 mg, 0.62 mmol) were dissolved in THF and stirred overnight. The product was extracted twice with a saturated solution of NaHCO₃ and once with 1 M HCl. The product was dried over MgSO₄, evaporated and purified by flash chromatography with 100% EtOAc. The final product was recrystallized in EtOAc (34 mg, 0.06 mmol, 11%). MP=186.9-189.6° C. (188.1° C.) ¹H NMR (400 MHz, DMSO-d₆) δ 8.47 (s, 1H), 7.87 (d, J=8.9 Hz, 2H), 7.47-7.26 (m, 6H), 7.16 (d, J=8.8 Hz, 2H), 7.02 (d, J=8.9 Hz, 1H), 6.15 (d, J=7.9 Hz, 1H), 5.26 (s, 2H), 4.41 (s, 1H), 3.47 (s, 1H), 1.99 (s, 2H), 1.88 (s, 2H), 1.45 (q, J=11.1, 10.3 Hz, 2H), 1.32 (q, J=11.2 Hz, 2H).