1442
R. Mꢀlnickꢁ, L. Kvapil, P. ꢂlézar, M. Grepl, J. Hlavá , A. Ly ka, and P. Hradil
Vol 45
Table 7
1H and 13C chemical shifts (ꢂ, ppm) of compounds 10, 11, 14 and 15 in DMSO-d6
Position
10
ꢂH
11
ꢂH
14
ꢂH
15
ꢂH
ꢂC
ꢂC
ꢂC
ꢂC
2
4
5
1´
2´
3´
4´
NH
-
155.1
130.1
105.8
122.1
122.9
128.8
126.3
-
-
-
-
-
152.4
127.9
129.3
135.0
128.0
129.0
129.3
-
-
-
156.2
127.2
124.8
126.9
124.1
129.0
127.4
-
-
-
-
-
160.5
173.2
138.8
128.3
130.6
129.3
134.4
-
hydrazo
142.9
114.8
129.6
123.2
-
6.93
-
7.54
7.73
-
7.60
7.47
7.38
11.42
8.11
7.56
7.47
11.77c,
11.20d
-
7.78
7.56
7.43
8.47
7.71
7.80
11.59
7.37
7.20
10.58a,
10.11b
azo
1´´
2´´
3´´
4´´
-
-
-
-
-
-
-
-
153.0
121.9
129.5
129.4
-
-
-
-
-
-
-
-
-
7.49
7.43
7.10
d
a 1J(15N, 1H) = 97.1 Hz, b 1J(15N, 1H) = 97.2 Hz, c 1J(15N, 1H) = 97.4 Hz, 1J(15N, 1H) = 99.6 Hz.
for C9H8N2O (M= 160.06): C, 67.51; H, 5.00; N, 17.5. Found C,
67.85; H, 4.77; N, 17.15.
Then dark solid was dissolved in ethanol, filtered with charcoal,
concentrated in vacuo and precipitated by diethyl ether. Solid
product was collected by filtration and dried. Yield of yellow
solid was 31.4 mg (70 %), mp 151-154 °C (lit. [21,22] mp 151
– 153 °C); ms: m/z (relative intensity) 162 (100) [M+H]+, 190
[M+C2H5]+, 202 [M+C3H5]+; MS2(162,w3,EV1), m/z 134
[M+H-CO]+, 118 [M+H-COO]+, 116(100) [M+H-COOH2]+, 91.
5-Phenyl-4-phenylazo-3-imidazolin-2-one (11). Imidazolinone
10 (2.23 g, 13.9 mmol) was suspended in ethanol (120 mL),
sodium acetate (7.5 g) was added and the reaction mixture was
heated to 40°C and diazonium salt (13.9 mmol) in water (12
mL) was added. Reaction was stirred at this temperature for 30
minutes. An orange suspension was formed immediately after
addition of the first drop of diazonium salt solution. Then the
reaction mixture was diluted by water and red product was
collected by filtration and crystallized from ethanol. The yield
after crystallization was 1 g, (27 %) of red product 11, mp 208-
211 °C (lit. [14] mp 200 °C); uv: ꢀ max 419.7 nm (ꢁ max 2.12.
104 l.mol-1.cm-1); ms: m/z (relative intensity) 265 (100) [M+H]+,
4-Phenyl-5-phenylazo-3-oxazolin-2-one (15).
Method A. Oxazolon 14 (200 mg, 1.24 mmol) was dissolved
in ethanol (20 mL) sodium acetate (0.31 g, 3.78 mmol) was
added and the reaction mixture was heated to 20°C and
diazonium salt (1.24 mmol) in water (12 mL ) was added. The
reaction was stirred at this temperature for 5 minutes, an orange
suspension was formed immediately after addition of the first
drop of diazonium salt solution. Then the reaction mixture was
diluted by water and red product was collected by filtration and
crystallized from ethanol. The yield after crystallization was
100 mg, (30 %) of red product, mp 232-235 °C; uv: ꢀ max 467.6
nm (ꢁ max 1.2 .103 l.mol-1.cm-1); ms: m/z (relative intensity) 266
(100) [M+H]+, 294 [M+C2H5]+, 306 [M+C3H5]+; ms2(266, w3,
EV1), m/z 264 [M-H]+, 238 [M+H-CO]+, 223, 222 [M+H-
COO]+, 220, 205, 195, 193, 167, 157, 144, 135, 131, 119, 109,
104, 92. Anal. Calcd. for C15H11N3O2 (M= 265.19): C, 67.94;
H, 4.15; N, 15.85. Found C, 67.6; H, 4.19; N, 15.81.
Method B. Carbamate 13 (55 mg, 0.31 mmol) were dissolved
in ethanol (15 mL), sodium acetate (74 mg, 0.93 mmol) was
added and solution of diazonium salts 3 (0.31 mmol) in water
were slowly added at temperature 40°C. The reaction mixture
was diluted by water (10 mL) after 5 minutes. The precipitated
solid product was collected by filtration and washed with water
after 30 minutes of stirring. The isolated product was
recrystallized from ethanol. The yield was 40 mg, (49 %) of
red product, mp 235-237 °C
293 [M+C2H5]+, 305 [M+C3H5]+;
MS2(265,w3,EV1), m/z
263[M-H]+, 248, 236, 222 [M+H-CONH]+, 220, 205, 195, 193,
187 [M+H-C6H6]+, 180, 167, 165, 162, 145, 135, 119, 104, 93.
Anal. Calcd. for C15H12N4O (M= 264.19): C, 68.2; H, 4.54; N,
21.21. Found: C, 68.44; H, 4.77; N, 20.92.
O-Phenacyl carbamate (13). 2-Hydroxyacetophenone (5.25
g, 38.6 mmol) was dissolved in toluene (54 mL) and N,N-
dimethylaniline (11.55 mL, 91.2 mmol) was added, the mixture
was cooled to -5 to 0 °C and solution of triphosgene (13.06 g, 44
mmol) in toluene (20 mL) was added. The reaction mixture was
stirred for an additional 30 minutes at 0°C then concentrated
ammonium hydroxide (45 mL) was added and the reaction
mixture was stirred for next 30 minutes. The reaction was then
quenched by the addition of sulfuric acid until a pH 3 is
obtained. The reaction was diluted with water (300 mL) and
ethyl acetate (100 mL). The organic layer was separated and the
aqueous layer was re-extracted with ethyl acetate (2 x 100 mL).
The combine organic layers were washed with brine (100 mL),
dried with sodium sulfate, filtered and concentrated in vacuo.
The product was collected by filtration, washed with ethyl
acetate to give 3.6 g, (59 %), mp 145-149 °C; ms: m/z (relative
intensity) 180 (10) [M+H]+, 208 [M+C2H5]+; ms2(180,w3,EV1):
m/z 163 [M+H-NH3]+, 137 (100) [M+H-CONH]+, 119
[C6H5COCH3]+, 91. Anal. Calcd. for C9H9NO3 (M= 179.11): C,
60.35; H, 5.02; N, 7.82. Found: C, 60.26; H, 5.08; N, 7.42.
4-Phenyl-4-oxazolin-2-one (14). Compound 13 (50 mg,
0.279 mol) was heated to 350 °C without solvent for 10 minutes.
Analytical measurement. MS characterization was carried
out using the DEP-CI-MS-MS (direct exposure probe-chemical
ionization-tandem mass spectrometry) technique with
quadrupole ion trap mass analyzer and methane as a CI reagent
gas. Results are summarized in Tables 2 and 4
The 1H, 13C and 15N NMR spectra were recorded on a Bruker
1
Avance spectrometer (500.13 MHz for H, 125.76 MHz for 13C