The Journal of Organic Chemistry
Article
1H), 7.50−7.46 (m, 2H), 7.42−7.28 (m, 7H), 7.10 (t, J = 8.6 Hz,
2H), 5.40 (d, J = 7.7 Hz, 1H), 5.20 (d, J = 7.7 Hz, 1H). 13C{1H}
NMR (126 MHz, CHCl3-d): δ 164.0, 163.7 (d, J = 246 Hz), 141.7,
136.2, 131.8, 128.9, 128.5, 127.9, 127.5 (d, J = 8 Hz), 127.3, 126.7,
125.7, 116.0 (d, J = 21.5 Hz), 88.4, 79.0. HRMS (ESI-TOF) m/z: [M
+ H]+ calcd for (C21H17FNO+), 318.1289; found, 318.1293.
4,5-Bis(4-(trifluoromethyl)phenyl)-2-phenyl-4,5-dihydrooxazole
(3k). Isolated as a white solid (79 mg, 72%). mp 98−101 °C. IR:
3058, 2924, 1694, 1322, 1109, 1062 cm−1. 1H NMR (500 MHz,
CHCl3-d): δ 8.14 (dd, J = 8.2, 1.0 Hz, 2H), 7.69 (dd, J = 14.7, 8.2 Hz,
4H), 7.62−7.58 (m, 1H), 7.53−7.47 (m, 4H), 7.43 (d, J = 8.2 Hz,
2H), 5.44 (d, J = 7.8 Hz, 1H), 5.26 (d, J = 7.8 Hz, 1H). 13C{1H}
NMR (126 MHz, CHCl3-d): δ 164.7, 145.3, 143.8, 132.2, 130.8 (q, J
= 32.7 Hz), 130.5 (q, J = 32.5 Hz), 128.7, 128.7, 127.2, 126.8, 126.1
(q, J = 3.4 Hz), 126.0 (q, J = 3.4 Hz), 126.0, 125.1, 122.8, 88.0, 78.7.
HRMS (ESI-TOF) m/z: [M + H]+ calcd for (C23H16F6NO+),
436.1131; found, 436.1134.
4,5-Bis(4-fluorophenyl)-2-phenyl-4,5-dihydrooxazole (3l). Iso-
lated as a white solid (48 mg, 57%). mp 85−88 °C. IR: 3053,
2923, 1650, 1604, 1507, 1319, 1219, 1063 cm−1. 1H NMR (500 MHz,
CHCl3-d): δ 8.17−8.06 (m, 2H), 7.59−7.53 (m, 1H), 7.48 (t, J = 7.6
Hz, 2H), 7.32 (m, 2H), 7.27−7.24 (m, 2H), 7.16−6.99 (m, 4H), 5.34
(d, J = 7.8 Hz, 1H), 5.17 (d, J = 7.8 Hz, 1H). 13C{1H} NMR (126
MHz, CHCl3-d): δ 164.1, 163.8 (d, J = 246 Hz), 163.4 (d, J = 245
Hz), 137.5 (d, J = 3 Hz), 135.9 (d, J = 3 Hz), 131.9, 128.6, 128.6,
128.4 (d, J = 8 Hz), 127.5 (d, J = 8 Hz), 127.2, 116.0 (d, J = 21.5 Hz),
115.7 (d, J = 21.5 Hz), 88.5, 78.4. HRMS (ESI-TOF) m/z: [M + H]+
calcd for (C21H16F2NO+), 336.1194; found, 336.1200.
5-(Benzo[d][1,3]dioxol-5-yl)-2,4-diphenyl-4,5-dihydro Oxazole
(3e). Isolated as a white solid (60 mg, 70%). mp 121−122 °C. IR:
3033, 2980, 1636, 1491, 1444, 1248, 1063, 1020 cm−1. 1H NMR (500
MHz, CHCl3-d): δ 8.18−8.10 (m, 2H), 7.58−7.53 (m, 1H), 7.48 (t, J
= 7.5 Hz, 2H), 7.39 (t, J = 7.2 Hz, 2H), 7.35−7.28 (m, 3H), 6.89 (s,
1H), 6.82 (s, 2H), 5.98 (s, 2H), 5.33 (d, J = 7.7 Hz, 1H), 5.23 (d, J =
7.7 Hz, 1H). 13C{1H} NMR (126 MHz, CHCl3-d): δ 164.0, 148.3,
147.8, 142.0, 134.2, 131.7, 128.9, 128.6, 128.5, 127.8, 127.5, 126.7,
119.7, 108.5, 106.2, 101.3, 89.1, 78.9. HRMS (ESI-TOF) m/z: [M +
+
H]+ calcd for (C22H18NO3 ), 344.1281; found, 344.1284.
2,4-Diphenyl-5-(pyren-4-yl)-4,5-dihydrooxazole (3f). Isolated as a
white solid (55 mg, 52%). mp 131−135 °C. IR: 3028, 2980, 1648,
1600, 1577, 1448, 1317, 1240, 1061 cm−1. 1H NMR (500 MHz,
CHCl3-d): δ 8.39−8.29 (m, 2H), 8.23−7.98 (m, 8H), 7.89 (d, J = 9.3
Hz, 1H), 7.61 (m, 3H), 7.53−7.35 (m, 5H), 6.53 (d, J = 7.2 Hz, 1H),
5.46 (d, J = 7.2 Hz, 1H). 13C{1H} NMR (126 MHz, CHCl3-d): δ
164.3, 142.0, 133.7, 131.9, 131.4, 131.3, 130.6, 129.0, 128.9, 128.7,
128.1, 128.1, 127.7, 127.6, 127.5, 127.5, 127.3, 126.2, 125.6, 125.4,
125.2, 125.1, 124.8, 122.9, 122.5, 86.9, 79.6. HRMS (ESI-TOF) m/z:
4,5-Bis(4-methoxyphenyl)-2-phenyl-4,5-dihydrooxazole (3m).
Isolated as a white solid (31 mg, 34%). mp 93−95 °C. IR: 3063,
2927, 1645, 1609, 1509, 1241, 1146, 1029 cm−1. 1H NMR (500 MHz,
CHCl3-d): δ 8.17−8.08 (m, 2H), 7.54 (t, J = 7.6 Hz, 1H), 7.47 (t, J =
7.6 Hz, 2H), 7.29 (d, J = 8.7 Hz, 2H), 7.22 (d, J = 8.7 Hz, 2H), 6.92
(dd, J = 14.1, 8.7 Hz, 4H), 5.34 (d, J = 7.8 Hz, 1H), 5.18 (d, J = 7.8
Hz, 1H), 3.83 (s, 3H), 3.82 (s, 3H). 13C{1H}NMR (126 MHz,
CHCl3-d): δ 163.8, 159.8, 159.2, 134.2, 132.4, 131.6, 128.6, 128.4,
127.9, 127.7, 127.3, 114.3, 114.2, 89.1, 78.3, 55.3, 55.3. HRMS (ESI-
+
[M + H]+ calcd for (C22H20NO2 ), 424.1696; found, 424.1699.
2,4-Diphenyl-5-((E)-styryl)-4,5-dihydrooxazole (3g). Isolated as a
white solid (52 mg, 64%). mp 105−108 °C. IR: 3025, 2924,1646,
1601, 1578, 1449, 1324, 1059 cm−1. 1H NMR (500 MHz, CHCl3-d):
δ 8.12 (dd, J = 8.3, 1.2 Hz, 2H), 7.57−7.53 (m, 1H), 7.50−7.43 (m,
4H), 7.43−7.27 (m, 8H), 6.68 (d, J = 15.8 Hz, 1H), 6.44 (dd, J =
15.8, 7.9 Hz, 1H), 5.17 (d, J = 7.9 Hz, 1H), 5.05 (td, J = 7.9, 0.7 Hz,
1H). 13C{1H} NMR (126 MHz, CHCl3-d): δ 164.0, 141.6, 135.9,
133.6, 131.7, 128.8, 128.7, 128.6, 128.5, 128.4, 127.8, 127.6, 126.8,
126.8, 126.6, 88.8, 76.4. HRMS (ESI-TOF) m/z: [M + H]+ calcd for
(C23H20NO+), 326.1539; found, 326.1544.
+
TOF) m/z: [M + H]+ calcd for (C23H22NO3 ), 360.1594; found,
360.1599.
5-(Benzo[d][1,3]dioxol-5-yl)-4-(4-fluorophenyl)-2-phenyl-4,5-di-
hydrooxazole (3n). Isolated as a yellowish solid (52 mg, 57%). mp
80−83 °C. IR: 3038, 2922, 1638, 1504, 1492, 1444, 1336, 1248, 1227,
1
2,4-Diphenyl-5-(4-(trifluoromethyl)phenyl)-4,5-dihydro Oxazole
1062, 1032 cm−1. H NMR (500 MHz, CHCl3-d): δ 8.14−8.08 (m,
(3h). Isolated as a mixture (51 mg, 55% yield) with its regioisomer
2H), 7.55 (d, J = 7.5 Hz, 1H), 7.49 (d, J = 7.8 Hz, 2H), 7.27−7.23
(m, 2H), 7.07 (t, J = 8.7 Hz, 2H), 6.86 (d, J = 1.6 Hz, 1H), 6.84−6.78
(m, 2H), 6.00 (s, 2H), 5.26 (d, J = 7.8 Hz, 1H), 5.18 (d, J = 7.8 Hz,
1H). 13C{1H} NMR (126 MHz, CHCl3-d): δ 164.1, 163.4 (d, J = 246
Hz), 148.3, 147.9, 137.7, 133.9, 131.8, 128.6, 128.5, 128.3 (d, J = 8
Hz), 127.3, 119.7, 115.8 (d, J = 21.5 Hz), 108.5, 106.1, 101.3, 89.2,
1
(3t). IR: 3032, 2988, 1675, 1650, 1320, 1281, 1063 cm−1. H NMR
(500 MHz, CHCl3-d): δ 8.18−8.13 (m, 2H), 7.67 (m, 2H), 7.59 (t, J
= 7.4 Hz, 1H), 7.52−7.31 (m, 9H), 5.49 (d, J = 7.7 Hz, 1H), 5.20 (d,
J = 7.7 Hz, 1H). 13C{1H} NMR (126 MHz, CHCl3-d): δ 164.0, 144.4,
141.4, 132.0, 130.5 (q, J = 32.4 Hz), 129.0, 128.7, 128.6, 128.1, 127.1,
126.8, 125.9 (q, J = 3.7 Hz), 125.9, 122.9, 88.1, 79.2. HRMS (ESI-
TOF) m/z: [M + H]+ calcd for (C22H17F3NO+), 368.1257; found,
368.1258.
5-(4-Methoxyphenyl)-2-phenyl-4-(4-(trifluoromethyl) phenyl)-
4,5-dihydrooxazole (3i). Isolated as a white solid (40 mg, 40%).
mp 99−101 °C. IR: 3062, 2925, 1647, 1513, 1322, 1247, 1064 cm−1.
1H NMR (500 MHz, CHCl3-d): δ 8.18−8.09 (m, 2H), 7.64 (d, J =
+
78.2. HRMS (ESI-TOF) m/z: [M + H]+ calcd for (C22H17FNO3 ),
362.1187; found, 362.1187.
5-(Benzo[d][1,3]dioxol-5-yl)-2-phenyl-4-(4-(trifluoro methyl)-
phenyl)-4,5-dihydrooxazole (3o). Isolated as a pink solid (64 mg,
62%). mp 87−90 °C. IR: 3067, 2904, 1638, 1487, 1447, 1319, 1247,
1127, 1065, 1038 cm−1. 1H NMR (500 MHz, CHCl3-d): δ 8.14−8.08
(m, 2H), 7.63 (d, J = 8.1 Hz, 2H), 7.56 (t, J = 7.4 Hz, 1H), 7.48 (t, J
= 7.6 Hz, 2H), 7.41 (d, J = 8.1 Hz, 2H), 6.87 (d, J = 1.4 Hz, 1H),
6.84−6.77 (m, 2H), 6.00 (s, 2H), 5.27 (s, 2H). 13C{1H} NMR (126
MHz, CHCl3-d): δ 164.6, 148.4, 148.1, 145.8, 133.6, 132.0, 129.9 (q,
J = 32.4 Hz), 128.6, 128.6, 127.2, 127.0, 125.8 (q, J = 3.7 Hz), 123.0,
119.9, 108.5, 106.2, 101.4, 89.0, 78.4. HRMS (ESI-TOF) m/z: [M +
8.1 Hz, 2H), 7.59−7.55 (m, 1H), 7.49 (t, J = 7.6 Hz, 2H), 7.42 (d, J =
8.1 Hz, 2H), 7.33−7.30 (m, 2H), 6.98−6.95 (m, 2H), 5.32 (s, 2H),
3.85 (s, 3H). 13C{1H} NMR (126 MHz, CHCl3-d): δ 164.7, 160.0,
146.0, 131.9, 131.7, 129.9 (q, J = 32.4 Hz), 128.7, 128.5, 127.5, 127.3,
127.1, 125.8 (q, J = 3.7 Hz), 123.1, 114.4, 88.9, 78.3, 55.4. HRMS
+
(ESI-TOF) m/z: [M + H]+ calcd for (C23H19F3NO2 ), 398.1362;
+
H]+ calcd for (C23H17F3NO3 ), 412.1155; found, 412.1157.
found, 398.1367.
4-(5-(Benzo[d][1,3]dioxol-5-yl)-2-phenyl-4,5-dihydro Oxazol-4-
yl)benzonitrile (3p). Isolated as a colorless solid (71 mg, 77%). mp
112−114 °C. IR: 3062, 2978, 2227, 1643, 1489, 1445, 1210, 1037
4-(4-Methoxyphenyl)-2-phenyl-5-(4-(trifluoromethyl) phenyl)-
4,5-dihydrooxazole (3j). Isolated as a white solid (combined yield
3i/3j (1:1) as poorly separable mixture is 69 mg, 69%). A small
amount of pure 3j was used for complete characterization. mp 95−97
1
cm−1. H NMR (500 MHz, CHCl3-d): δ 8.10 (d, J = 8.3 Hz, 2H),
7.68 (d, J = 8.3 Hz, 2H), 7.58 (t, J = 7.4 Hz, 1H), 7.49 (t, J = 7.6 Hz,
2H), 7.41 (d, J = 8.3 Hz, 2H), 6.88−6.82 (m, 2H), 6.80 (dd, J = 8.0,
1.7 Hz, 1H), 6.01 (s, 2H), 5.27 (d, J = 8.0 Hz, 1H), 5.23 (d, J = 8.0
Hz, 1H). 13C{1H} NMR (126 MHz, CHCl3-d): δ 164.9, 148.5, 148.2,
147.1, 133.2, 132.7, 132.1, 128.7, 128.6, 127.4, 126.9, 120.0, 118.7,
111.7, 108.6, 106.2, 101.4, 88.9, 78.3. HRMS (ESI-TOF) m/z: [M +
1
°C. IR: 3063, 2926, 1646, 1514, 1322, 1248, 1065 cm−1. H NMR
(500 MHz, CHCl3-d): δ 8.12 (d, J = 7.6 Hz, 2H), 7.66 (d, J = 8.1 Hz,
2H), 7.57 (t, J = 7.3 Hz, 1H), 7.53−7.41 (m, 4H), 7.22 (d, J = 8.5 Hz,
2H), 6.92 (d, J = 8.5 Hz, 2H), 5.44 (d, J = 7.7 Hz, 1H), 5.12 (d, J =
7.7 Hz, 1H), 3.82 (s, 3H). 13C{1H} NMR (126 MHz, CHCl3-d): δ
163.7, 159.4, 144.5, 133.5, 131.9, 130.7 (q, J = 32.4 Hz), 128.6, 128.6,
128.0, 127.2, 125.9 (q, J = 3.7 Hz), 125.8, 125.1, 114.4, 88.2, 78.8,
+
H]+ calcd for (C23H17N2O3 ), 369.1234; found, 369.1234.
5-(Benzo[d][1,3]dioxol-5-yl)-2-(4-methoxyphenyl)-4-phenyl-4,5-
dihydrooxazole (3q).21 Isolated as a white solid (69 mg, 74%). mp
93−95 °C. IR: 3029, 2979, 1643, 1608, 1501, 1488, 1446, 1339, 1243,
+
55.4. HRMS (ESI-TOF) m/z: [M + H]+ calcd for (C23H19F3NO2 ),
398.1362; found, 398.1365.
F
J. Org. Chem. XXXX, XXX, XXX−XXX