Potassium Carbonate → HCID 68213907, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 1,2-bis(tert-butoxycarbonyl)-1-[3-bromo-4-hydroxybenzyl]-guanidine (for synthesis, see, for example, Purohit et al., International PCT Patent Publication No. WO2008/083056, incorporated herein by reference) (2.0 g, 4.51 mmol) dissolved in anhydrous DMF (45 mL) was added K2CO3 (1.12 g, 8.13 mmol), and 3-bromopropanol (816 mg, 5.87 mmol) and the reaction mixture warmed to 50° C. using an oil bath. After 2 h, the reaction mixture was diluted with water (30 mL), and the aqueous layer separated then extracted with EtOAc (3×100 mL). The combined organic layers were dried over MgSO4, filtered and concentrated to a solid. The crude material was purified using silica gel chromatography (4:1 to 3:2 hexanes:EtOAc) to yield a white solid product (2.00 g, 88% yield). 1H NMR (CDCl3, 600 MHz): δ 9.42 (brs, 1H), 9.27 (brs, 1H), 7.54 (d, J=1.8 Hz, 1H), 7.26 (m, 1H), 6.85 (d, J=2.4 Hz, 1H), 5.08 (brs, 2H), 4.19 (t, J=5.4 Hz, 2H), 3.92 (m, 2H), 2.16 (m, 1H), 2.18 (m, 2H), 1.51 (s, 9H), 1.43 (s, 9H); 13C NMR (CDCl3, 150 MHz): δ 163.8, 160.8, 155.0, 154.3, 144.8, 133.1, 132.6, 127.9, 113.0, 111.7, 84.7, 79.2, 67.8, 60.6, 46.7, 31.9, 28.5, 28.3.

Provenance & Evidence