Cu‑Catalyzed Oxidative‑Reaction of Tosylmethylisocyanide and Benzyl Alcohols: Eꢀcient…
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3
+
+
Ar), 7.94–7.97 (2H, d, J = 15 Hz, Ar); C NMR (CDCl ,
131.2, 164.0, 164.1, 164.8. MS for C H NO : calcd.[M]
3
10
9
3
1
1
25 MHz, δ, ppm): C 28.4, 55.1, 85.5, 127.7, 129.5, 130.6,
191.1, found 191.2. Elemental Analysis: calcd. C, 62.82, H,
+
33.8, 150.2, 164.9, 184.7. MS for C H ClNO : calcd.
4.75, N, 7.33 found C, 62.82, H, 4.76, N, 7.34.
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3
14
4
+
1
[
M] 283.1, found 283.1. Elemental Analysis: calcd. C,
4b: Colorless liquid. H NMR (CDCl , 300 MHz, δ,
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5
5.04, H, 4.97, N, 4.94, found C, 55.04, H, 4.96, N, 4.95.
ppm): H 3.70 (3H, s 2 OCH ), 6.13 (1H, s, OCH), 6.72 (1H,
3
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3
d: Colorless liquid. H NMR (CDCl , 300 MHz, δ,
d, J=9 Hz, Ar), 7.03 (1H, s, Ar), 7.35 (1H, d, J=9 Hz, Ar),
3
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3
ppm): H 1.63 (9H, s, C(CH ) ), 6.98 (2H, dd, J = 15 Hz,
8.85 (1H, s, NCH); C NMR (CDCl , 125 MHz, δ, ppm):
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3
o
3
J = 5 Hz,Ar), 7.96 (2H, dd, J = 15 Hz, J = 5 Hz, Ar);
C 56.7, 57.4, 92.5, 101.0, 111.0, 118.1, 128.4, 157.3, 161.3,
p
o
p
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3
C NMR (CDCl , 125 MHz, δ, ppm): C 28.7, 55.7, 85.1,
163.9, 166.6.
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23.5, 127.7, 129.5, 163.7, 169.0(d, J=40 Hz), 184.9. MS
4c: Pale-yellow liquid. H NMR (CDCl , 300 MHz, δ,
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+
+
for C H FNO : calcd.[M] 267.1, found 267.1. Elemental
ppm): H 3.66 (3H, s, NCH ), 3.69 (3H, s, NCH ), 6.12 (1H,
13
14
4
3
3
Analysis: calcd. C, 58.42, H, 5.28, N, 5.24, found C, 58.42,
s, OCH), 7.35 (2H, d, J=9 Hz, Ar), 7.76 (1H, d, J=9 Hz,
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H, 5.30, N, 5.26.
Ar),8.87 (1H, s, NCH); C NMR (CDCl , 125 MHz, δ,
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3
e: Colorless liquid. H NMR (CDCl , 300 MHz,
ppm): C 42.3, 91.3, 115.8, 128.8, 131.0, 154.3, 164.5, 165.7.
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δ, ppm): H 1.60 (9H, s, C(CH ) ), 3.87 (6H, s, 2OCH ),
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3
3
1
3
6
.43–6.62 (2H, m, Ar), 7.90–7.94 (1H, m, Ar); C NMR
(
CDCl , 125 MHz, δ, ppm): C 28.1, 55.6, 55.6, 55.7, 84.4,
3 Results and Discussion
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9
8.6, 104.4, 110.3, 132.4, 164.1, 164.8, 166.0, 185.8. MS
+
+
for C H NO : calcd.[M] 309.1, found 309.1. Elemental
The reaction of TosMIC1 and 4-methoxybenzyl alcohol
2a was chosen as a model reaction to optimize the reaction
conditions. Initially, TosMIC and 4-methoxybenzyl alcohol
were added to the acetonitrile in the presence of TBHP and
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5
19
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Analysis: calcd. C, 58.25, H, 6.19, N, 4.53, found C, 58.25,
H, 6.20, N, 4.53.
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f: Colorless liquid. H NMR (CDCl , 300 MHz, δ, ppm):
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H 1.58 (9H, s, C(CH ) ), 2.28 (6H, s, 2CH ), 2.31 (3H, s,
piperidine and heated at 70 °C in the presence of CuCl for
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2
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3
CH ), 6.88 (1H, s, Ar); C NMR (CDCl , 125 MHz, δ,
6 h. After the formation of 5-(4-methoxyphenyl)-4-tosylox-
azolidin-2-one A as the ꢀrst intermediate, acetic acid was
added to the reaction mixture. To our surprise, after 6 h, the
product 4-(tert-butylperoxy)-5-(4-methoxyphenyl)oxazol-
2(3H)-one 3a was produced (Scheme 1).
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3
ppm): C 28.3, 29.9, 31.7, 55.46, 85.44, 127.3, 130.3, 133.1,
+
+
1
37.9, 164.6, 184.5. MS for C H NO : calcd.[M] 291.1,
16 21 4
found 291.1. Elemental Analysis: calcd. C, 65.96, H, 7.27,
N, 4.81, found C, 65.96, H, 7.28, N, 4.81.
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B: Orange powder. 202–204 °C. H NMR (DMSO-d ,
The structure of product 3a was assigned from its elemen-
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00 MHz, δ, ppm): H 2.43 (3H, s, CH ), 5.62 (1H, d J
tal analyses as well as H NMR, C NMR, and mass spectral
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.8 Hz, CH), 6.15 (1H, d J 4.8 Hz, CH), 7.47–7.56 (4H, m,
data. The H NMR spectrum of 3a exhibited two singles
arom), 7.78 (1H, s, NCHO), 7.83 (2H, d, J 7.5 Hz, arom),
signals at 1.63 and 3.90 ppm corresponding to t-butyl and
methoxy groups and two multiple peaks for four aromatic
hydrogens at 6.93–7.00 and 7.91–7.98 ppm. In addition,
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.28 (2H, d, J 7.5 Hz, arom); C NMR (DMSO-d , 75 MHz,
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δ, ppm): C 21.6, 78.1, 91.3, 124.5, 127.5, 129.2, 129.9,
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30.3, 145.2, 145.9, 148.2, 160.4.
H-decoupled C NMR spectrum of 3a showed 10 distinct
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C: Yellow solid. 184–187 °C. H NMR (DMSO-d ,
resonances in agreement with the proposed structure. The
mass spectrum, as expected, conꢀrms its molecular weight.
The model reaction was carried out in dichloromethane,
toluene, p-xylene, and under solvent-free conditions to eval-
uate the eꢃect of solvents. As Table 1 indicates, toluene and
p-xylene were found to be suitable solvents. The reaction
yield was low under solvent-free conditions, and in dichlo-
romethane, no reaction took place. Also, the catalytic activ-
ity of various copper salts, nickel, and cobalt chlorides was
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00 MHz, δ, ppm):H 7.99 (2H, d, J 8.7 Hz, arom), 8.02
(
1H, s, CCHN), 8.33 (2H, d, J 8.7 Hz, arom), 8.62 (1H, s,
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NCHO); C NMR (DMSO-d , 75 MHz, δ, ppm): C 125.0,
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25.4, 126.1, 133.7, 147.3, 153.9, 156.4.
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4
a: Colorless liquid. H NMR (CDCl , 300 MHz, δ,
3
ppm): H 3.90 (3H, s, OCH ), 5.32 (1H, s, OCH), 6.97 (2H,
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3
br, Ar), 7.28 (1H, s, CH=N), 7.90 (2H, br, Ar); C NMR
(
CDCl , 125 MHz, δ, ppm): C 55.6, 90.4, 114.2, 125.6,
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Scheme 1 Synthesis of4-(tert-
butylperoxy)-oxazolone3a
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