Synthesis of 2,5-(4-alkoxybenzoyloxy)benzyl acrylates…
69
for C7H8O3 (MH?): 140.0473; found: 140.0476. Elemental analysis: calc 59.99 %
C, 5.75 % H; found 59.88 % C and 5.65 % H.
Synthesis of 6
2-(hydroxymethyl)benzene-1,4-diol (5) (100 mg, 0.71 mmol) was dissolved in
10 mL CH3CN. To the solution, pyridinium p-toluenesulphonate (178 mg,
0.71 mmol) was added. To the mixture a solution of 3,4-dihydro-2H-pyran
(60 mg, 0.71 mmol) in 10 mL CH3CN was added. The mixture was stirred at r.t.
for 48 h. After removal of the solvent under vacuum, the residue was purified by
column chromatography (SiO2, PE/EtOAc = 1:1) to afford compound 6 (80 mg,
yield: 50 %). IR (neat): 3306, 3035, 2870, 1613, 1455 cm-1. 1H-NMR ((CD3)2SO):
d 8.71 (s, 1H), 8.65 (s, 1H), 6.70 (d, J = 2.8 Hz, 1H), 6.60–6.55 (m, 1H), 6.49–6.46
(m, 1H), 4.67–4.66 (m, 1H), 4.56 (d, J = 12.4 Hz, 1H), 4.36 (d, J = 12.4 Hz, 1H),
3.83–3.77 (m, 1H), 3.49–3.45 (m, 1H), 1.76–1.72 (m, 1H), 1.68–1.62 (m, 1H),
1.53–1.47 (m, 4H). 13C-NMR ((CD3)2SO): d 150.1, 147.4, 125.7, 115.9, 115.3,
114.7, 97.8, 63.8, 61.6, 30.7, 25.5, 19.5. HRMS (FAB) calcd for C12H16O4 (MH?):
224.1049; found: 224.1051. Elemental analysis: calc 64.27 % C, 7.19 % H; found
64.20 % C and 7.10 % H.
Synthesis of 7a (method A)
To a mixture of 4-butoxybenzoic acid (110 mg, 0.57 mmol) and DCC (120 mg,
0.58 mmol) in 3 mL CH2Cl2 was added a solution of 6 (40 mg, 0.18 mmol) and
DMAP (70 mg, 0.57 mmol) in 3 mL CH2Cl2. The mixture was stirred at r.t. for
12 h. After removal of the solvent under vacuum, the residue was purified by
column chromatography (SiO2, PE/EtOAc = 5:1) to afford compound 7a (51 mg,
yield: 46 %).IR (neat): 2640, 2360, 1728, 1720, 1660, 1644, 1468, 1392, 1164,
1
1072 cm-1. H-NMR (CDCl3): d 8.18–8.16 (m, 4H), 7.42 (d, J = 2.4 Hz, 1H),
7.28–7.20 (m, 2H), 7.01–6.99 (m, 4H), 4.80 (d, J = 12.8 Hz, 1H), 4.68 (t,
J = 3.2 Hz, 1H), 4.55 (d, J = 12.8 Hz, 1H), 4.08 (t, J = 6.4 Hz, 4H), 3.85–3.79
(m, 1H), 3.50–3.45 (m, 1H), 1.87–1.80 (m, 5H), 1.68–1.43 (m, 9H), 1.02 (t,
J = 7.6 Hz, 6H). 13C-NMR (CDCl3): d 164.8, 164.5, 163.6, 163.5, 148.6, 146.1,
132.3, 132.3, 132.2, 123.3, 122.2, 121.6, 121.2, 114.3, 114.3, 97.9, 68.0, 63.7, 61.8,
31.1, 30.3, 25.4, 19.2, 19.1, 13.8. HRMS (FAB) calcd for C34H40O8 (MH?):
576.2723; found: 576.2720. Elemental analysis: calc 70.81 % C, 6.99 % H; found
70.64 % C and 6.87 % H.
Synthesis of 7b (method B)
To a mixture of 6 (151 mg, 0.67 mmol) and DMAP (246 mg, 2.01 mmol) in 15 mL
CH2Cl2 DIC (255 mg, 2.02 mmol) was added. The mixture was stirred for 10 min.
To the mixture, a solution of 4-ethoxybenzoic acid (336 mg, 2.02 mmol) in 15 mL
CH2Cl2 was added. The mixture was stirred at r.t. for 12 h. After removal of the
solvent under vacuum, the residue was purified by column chromatography (SiO2,
PE/EtOAc = 5:1) to afford compound 7b (153 mg, yield: 41 %). IR (neat): 2640,
123