1510 Bull. Chem. Soc. Jpn. Vol. 81, No. 11 (2008)
Electrochemical Oxidation of 4-Methylcatechol
1
Table 1. Experimental Conditions for Synthesis and Purifi-
cation of Products
6b: Mp 178–181; H NMR (90 MHz, Acetone-d6): ꢁ 0.99 (s,
6H), 1.93 (s, 3H), 2.14 (s, 4H), 6.48 (s, 1H), 6.65 (s, 1H), 7.71 (br
s, 3H); 13C NMR (22.5 MHz, Acetone-d6): ꢁ 19.7, 28.3, 30.3, 47.7,
109.4, 118.2, 119.9, 124.4, 131.0, 143.9, 145.6, 184.7; MS (20 eV,
EI): m=z (%): 262 (23), 244 (16), 188 (19), 124 (100), 83 (75), 78
(53), 56 (43), 39 (62); IR (KBr): ꢄ ¼ 3418, 2952, 1616, 1587,
1517, 1370, 1345, 1212, 1043, 1028, 865, 610.
Applied
potentiala)/V
Synthesis
solvent system
Isolated
yield/%
Conversion
1 ! 2f
1 ! 3f
1 ! 4f
1 ! 5b
1 ! 6b
1 ! 6d
1 ! 7b
0.4
0.4
0.4
0.2
0.2
0.4
0.2
H2O/AN (80/20)
H2O/AN (60/40)
H2O/AN (70/30)
H2O
86b)
89b)
77b)
92c)
82c)
51b)
68c)
1
6d: Mp 143–147; H NMR (90 MHz, Acetone-d6): ꢁ 1.1 (s,
6H), 1.80 (s, 3H), 2.25 (s, 2H), 2.80 (s, 2H), 3.17 (d, J ¼ 13 Hz,
1H), 3.41 (d, J ¼ 13 Hz, 1H), 6.28 (s, 1H); 13C NMR (22.5
MHz, CDCl3): ꢁ 27.2, 29.1, 30.8, 34.8, 50.7, 51.6, 77.3, 104.5,
108.6, 165.5, 170.2, 185.1, 192.4, 193.2; IR (KBr): ꢄ ¼ 2930,
1731, 1649, 1597, 1542, 1405, 1255, 1084, 900, 697.
7b: Mp 163–166; 1H NMR (90 MHz, Acetone-d6): ꢁ 1.56–
2.24 (m, 14H), 6.36 (s, 1H), 6.48 (s, 1H), 7.72 (br s, 2H); MS
(20 eV, EI): m=z (%): 262 (24), 244 (18), 220 (100), 187 (50),
149 (83), 137 (65), 97 (35), 69 (48), 43 (67); IR (KBr):
ꢄ ¼ 3424, 2940, 1725, 1701, 1653, 1608, 1503, 1289, 1195,
1101, 863.
H2O
H2O
H2O
a) Applied potential vs. SCE b) Crystallization solvent: hex-
ane/ethyl acetate. c) Crystallization solvent: diethyl ether/
chloroform.
solid was collected by filtration and then recrystallized by slow
diffusion of hexane or diethyl ether vapor into ethyl acetate or
chloroform respectively (Table 1). After recrystallization, prod-
1
ucts were characterized by: IR, H NMR, 13C NMR, MS, and X-
We thank Professor Issa Yavari for helpful discussions, also
financial support from the Research Affairs of Bu-Ali Sina
University is gratefully acknowledged.
ray. Table 1 shows the conditions and yield of isolated products.
Compounds Characteristics. 2f: Mp 158–161; 1H NMR
(300 MHz, CDCl3): ꢁ 1.39 (s, 3H), 1.74 (s, 3H), 3.13 (d, J ¼
15 Hz, 1H), 3.52 (d, J ¼ 15 Hz, 1H), 6.14 (s, 1H), 7.50 (t,
J ¼ 7:8 Hz, 2H), 7.63 (t, J ¼ 7:8 Hz, 1H), 7.73 (d, J ¼ 7:8 Hz,
2H); 13C NMR (75 MHz, CDCl3): ꢁ 16.8, 30.5, 51.5, 88.5,
114.2, 115.0, 128.7, 128.9, 133.5, 138.0, 171.3, 178.2, 182.4,
190.0, 190.6; MS (20 eV, EI): m=z (%): 283 (27), 282 (27), 254
(50), 241 (100), 240 (100), 239 (100), 225 (100), 212 (100), 211
(100), 197 (100), 183 (70), 165 (100), 152 (75), 115 (75), 105
(100), 77 (100), 43 (43); IR (KBr): ꢄ ¼ 3065, 2983, 2915, 1732,
1660, 1637, 1597, 1405, 1308, 1253, 949, 900, 740, 702. Crystal-
lographic data have been deposited with Cambridge Crystallo-
graphic Data Centre: Deposition number CCDC-653923 for com-
pound 2f. Copies of the data can be obtained free of charge via
Crystallographic Data Centre, 12, Union Road, Cambridge, CB2
1EZ, UK; Fax: +44 1223 336033; e-mail: deposit@ccdc.cam.
ac.uk).
Supporting Information
Copies of H, 13C NMR, FTIR, and MS of all compounds 2f–
4f, 6d, and 5b–7b. This material is available free of charge on
1
References
1
U. Jurva, H. V. Wikstrom, L. Weidolf, A. P. Bruins, Rapid
¨
T. Shono, Electroorganic Synthesis, Academic Press, San
Diego, 1991, Vol. 2.
2
3
4
D. Nematollahi, M. S. Workentin, E. Tammari, Chem.
5
D. Nematollahi, A. Afkhami, E. Tammari, T.
3f: Mp 181–183; 1H NMR (300 MHz, CDCl3): ꢁ 1.81 (s, 3H),
3.54 (d, J ¼ 14:4 Hz, 1H), 3.70 (d, J ¼ 14:4 Hz, 1H), 6.22 (s, 1H),
7.32–7.40 (m, 3H), 7.46–7.54 (m, 5H), 7.79 (d, J ¼ 5:9 Hz, 2H);
13C NMR (75 MHz, CDCl3): ꢁ 30.8, 51.4, 88.5, 112.9, 114.6,
128.3, 129.0, 129.1, 129.5, 129.7, 129.8, 133.2, 134.0, 137.4,
172.8, 174.3, 178.5, 190.9, 191.7; MS (20 eV, EI): m=z (%): 344
(25), 327 (20), 300 (65), 239 (18), 105 (100), 77 (100); IR
(KBr): ꢄ ¼ 3059, 2972, 1773, 1653, 1536, 1393, 1248, 886,
734, 691.
6
7
A. R. Fakhari, D. Nematollahi, M. Shamsipur, S.
Makarem, S. S. H. Davarani, A. Alizadeh, H. R. Khavasi, Tetra-
8
S. S. H. Davarani, D. Nematollahi, M. Shamsipur, N. M.
A. B. Moghaddam, F. Kobarfard, A. R. Fakhari, D.
1
4f: Mp 176–178; H NMR (90 MHz, Acetone-d6): ꢁ 1.76 (s,
9
3H), 3.35 (d, J ¼ 14:4 Hz, 1H), 3.49 (d, J ¼ 14:4 Hz, 1H), 6.24
(s, 1H), 6.95–7.69 (m, 2H), 8.03–8.50 (m, 4H); MS (20 eV, EI):
m=z (%): 316 (28), 301 (100), 283 (25), 255 (24), 196 (31), 149
(26), 69 (36), 55 (54), 43 (77); IR (KBr): ꢄ ¼ 2950, 1732, 1677,
1605, 1550, 1503, 1351, 1207, 1105, 896, 759.
12 D. Nematollahi, D. Habibi, M. Rahmati, M. Rafiee, J. Org.
1
5b: Mp 149–151; H NMR (90 MHz, Acetone-d6): ꢁ 1.75 (s,
6H), 1.96 (s, 3H), 6.56 (s, 1H), 6.74 (s, 1H) 7.77 (br s, 2H), 16.63
(s, 1H); 13C NMR (22.5 MHz, Acetone-d6): ꢁ 19.5, 24.0, 114.5,
118.4, 119.4, 128.5, 130.2, 144.5, 146.1, 192.3; MS (20 eV, EI):
m=z (%): 222 (15), 204 (13), 179 (12), 161 (56), 137 (16), 115
(18), 69 (21), 43 (100); IR (KBr): ꢄ ¼ 3503, 3258, 1583, 1517,
1375, 1318, 1185, 972, 872, 814, 636.