Reaction Steps
A mixture of 4-hydroxybenzaldehyde 1 (3, 0.60 kg, 4.91 mol), ethyl-6-bromohexanoate 2 (4, 1.10 kg, 4.91 mol), and K2CO3 (1.36 kg, 9.83 mol) in DMF (2 L) was stirred at 50° C. for 20 h. The mixture was filtered to remove remaining K2CO3. The resulting solution was concentrated in vacuo, diluted with EtOAc (3 L) and subsequently washed with saturated aqueous NaCl (3×1.5 L). The organic layer was dried (MgSO4), filtered and concentrated in vacuo to give an off white solid (3, 1.23 kg, 4.66 mol, 95%) with no need for further purification: M.p.: 33-35 ° C. 1H NMR (400 MHz, CDCl3) δ=9.87 (s, 1H), 7.81 (d, J=8.7, 2H), 6.97 (d, J=8.7, 2H), 4.12 (q, J=7.1, 2H), 4.04 (t, J=6.4, 2H), 2.33 (t, J=7.4, 2H), 1.82 (m, 2H), 1.69 (m, 2H), 1.53 (m, 2H), 1.25 (t, J=7.1, 3H); 13C NMR (400 MHz, CDCl3) δ=191.0, 173.7, 164.3, 132.1 (2C), 130.1, 114.9 (2C), 68.3, 60.5, 34.4, 29.0, 25.8, 24.8, 14.4; IR (film) ν=2941, 1719, 1688, 1595, 1579, 1509, 1466, 1392, 1307, 1252, 1213, 1155, 1108, 1030, 999, 832 cm−1; HRMS (MALDI-FTMS) m/z 287.1254 (287.1254 calculated for C15H20O4Na, (M+Na)+).
