“…The 1 H NMR spectrum of 1 showed three multiplets assignable to a 1,3-disubstituted propane unit at δ 2.99 (2H, quartet, J = 6.6 Hz, H 2 -4), 1.60 (2H, quintet, J = 6.6 Hz, H 2 -3), and 2.28 (2H, t, J = 6.6 Hz, H 2 -2), one doublet sp 3 methylene at δ 4.51 (2H, d, H-7′) and an ester methoxyl singlet at δ 3.58 (3H, s, O CH3), and two exchangeable broad triplets assigned to amino protons at δ 5.85 (1H, brt, J = 4.8 Hz, N′-H) and 5.84 (1H, brt, J = 6.6 Hz, N–H). The 13 C NMR data for 1 revealed the carbon signals associated with the above structural units (Table 1) as well as a set of resonances for the 2,3,6-tribromo-4,5-dihydroxybenzyl unit [2,3,4,5,6,7,8] and two additional signals associated to ester carbonyl carbon at δ 173.2 (C-1) and one sp 2 -hybridized quaternary carbon at δ 157.4 (C-5). The NMR signals of protons and corresponding carbons were assigned by the 1 H– 1 H COSY and HSQC experiments (Table 1).…”