The Journal of Organic Chemistry
Page 12 of 26
Compound 4d’: M.p. = 135-138 °C. R
f
0.69 (DCM/EtOAc 10/1). IR (neat): 3012, 2933, 2863, 1722, 1628, 1595, 1491, 1446, 1409, 1361, 1301, 1223, 1148,
1
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9
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-
1 1
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1
051, 936, 898, 842, 775, 712 cm . H NMR (300 MHz, CDCl ) δ 7.71 (s, 1H), 6.64 (s, 1H), 3.91 (s, 3H), 3.24 (t, J = 6.3 Hz, 2H), 2.77 (t, J = 7.0 Hz, 2H),
3
.91 (p, J = 6.7 Hz, 2H), 1.52 (s, 9H). 13C NMR (101 MHz, CDCl
) δ 170.8, 156.3, 137.8, 131.5, 131.0, 120.7, 111.4, 57.1, 56.2, 42.8, 31.4, 30.4, 28.8 (3 C).
3
+
HRMS: (ES-MS) m/z calculated for C15
Compound 4d’’: M.p. = 135-138 °C. R
189, 1141, 1062, 917, 883, 801, 716, 671 cm . H NMR (400 MHz, CDCl
H
21ClNO
2
[M+H] : 282.1255, found 282.1260.
f
0.45 (DCM/EtOAc 10/1). IR (neat): 3194, 3079, 2952, 2862, 1726, 1633, 1592, 1562, 1476, 1439, 1387, 1301, 1260,
-1 1
1
3
) δ 7.58 (d, J = 8.6 Hz, 1H), 6.85 (d, J = 8.6 Hz, 1H), 3.91 (s, 3H), 3.21 (t, J = 6.2
Hz, 2H), 3.06 (t, J = 6.8 Hz, 2H), 1.88 (p, J = 6.6 Hz, 2H), 1.55 (s, 9H). 13C NMR (101 MHz, CDCl
) δ 171.1, 156.6, 136.5, 134.3, 132.4, 128.1, 109.6, 57.2,
3
+
56.3, 42.9, 30.3, 28.9 (3 C), 25.8. HRMS (ES-MS): m/z calculated for C15
H
21ClNO
2
[M+H] : 282.1255, found 282.1261.
0
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-tert-butyl-7,8-dimethoxy-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (4e’) and 2-tert-butyl-6,7-dimethoxy-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (4e’’).
Compounds 4e’ and 4e’’ were prepared from 1x (468.5 mg, 1.0 mmol) and [Ir(dtb-bpy)(ppy) ]PF (9.3 mg, 10.2 µmol, 1 mol%) as catalyst following the
2
6
general protocol. For column chromatography neutral aluminum oxide (hexanes/EtOAc 4/1) was used. Yield 4e’: 134.0 mg (0.483 mmol, 48%) pale yellow
solid. Yield 4e’’: 28.6 mg (0.103 mmol, 10%) pale yellow solid.
Compound 4e’: M.p. = 130-132 °C (decomposition). R 0.24 (hexanes/EtOAc 4/1). Ir (neat): 2963, 2930, 2863, 1625, 1599, 1536, 1446, 1415, 1368, 1334,
f
-1 1
1282, 1261, 1215, 1033, 1088, 1029, 957, 869, 783 cm . H NMR (300 MHz, CDCl
3
) δ 7.25 (s, 1H), 6.58 (s, 1H), 3.88 (s, 6H), 3.25 (t, J = 6.3 Hz, 2H), 2.73
t, J = 7.0 Hz, 2H), 1.89 (p, J = 6.7 Hz, 2H), 1.53 (s, 9H). 13C NMR (75 MHz, CDCl
) δ 172.2, 150.4, 147.5, 130.9, 130.2, 111.9, 110.9, 56.9, 56.0, 55.9, 43.0,
[M+H] : 278.1751, found 278.1757.
0.33 (hexanes/EtOAc 4/1). Ir (neat): 2963, 2930, 2863, 1629, 1599, 1510, 1450, 1417, 1383, 1359,
1260, 1215, 1077, 1029, 958, 869, 749 cm . H NMR (300 MHz, CDCl ) δ 7.44 (d, J = 8.5 Hz, 1H), 6.83 (d, J = 8.6 Hz, 1H), 3.87 (s, 3H), 3.75 (s, 3H), 3.23
t, J = 6.3 Hz, 2H), 2.89 (t, J = 6.9 Hz, 2H), 1.54 (s, 9H). 13C NMR (75 MHz, CDCl
) δ 170.7, 153.4, 143.9, 130.9, 130.4, 124.1, 108.8, 60.2, 55.9, 54.7, 41.9,
[M+H] : 278.1751, found 278.1753.
(
3
+
3
1.9, 30.1, 28.8 (3 C). HRMS (ES-MS): m/z calculated for C16
H24NO
3
Compound 4e’’: M.p. = 132-134 °C (decomposition). R
f
-1 1
3
(
3
+
2
9.9, 27.8 (3 C), 20.4. HRMS (ES-MS): m/z calculated for C16
H24NO
3
2
-tert-butyl-6,7,8-trimethoxy-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (4f).
Compound 4f was prepared from 1y (50.0 mg, 0.1 mmol) and [Ir(dtb-bpy)(ppy)
For column chromatography neutral aluminum oxide (hexanes/EtOAc 4/1) was used. Yield 4f: 20 mg (65 µmol, 43%) pale yellow solid.
M.p. = 105-107 °C . R 0.52 (hexanes/EtOAc 4/1). IR (neat): 2960, 2937, 1752, 1722, 1636, 1592, 1484, 1457, 1416, 1387, 1323, 1241, 1193, 1111, 1074,
2
]PF (1.87 mg, 10.2 µmol, 2 mol%) as catalyst following the general protocol.
6
f
-1
1
1
6
2
033, 954, 917, 857, 809, 690 cm . H NMR (300 MHz, CDCl ) δ 7.04 (s, 1H), 3.86 (s, 3H), 3.84 (s, 3H), 3.77 (s, 3H), 3.22 (t, J = 6.2 Hz, 2H), 2.79 (t, J =
3
.9 Hz, 2H), 1.89 – 1.76 (m, 2H), 1.52 (s, 9H). 13C NMR (75 MHz, CDCl
) δ 171.7, 151.8, 150.0, 144.1, 133.9, 123.7, 108.1, 61.6, 60.9, 57.1, 56.0, 42.9, 31.4,
3
+
8.8 (3 C), 20.9. HRMS (ES-MS): m/z calculated for C17
H26NO
4
[M+H] : 308.1856, found 308.1863.
N-tert-butyl-2,6-dimethoxy-N-propylbenzamide (5).
Compound 5 was prepared from 1z (424.0 mg, 0.905 mmol) and [Ir(dtb-bpy)(ppy)
2
]PF
6
(10.1 mg, 11.1 µmol, 1.2 mol%) following the general protocol. Yield
) δ 7.19 (t, J = 8.4 Hz, 1H), 6.52 (d, J = 8.4 Hz, 2H),
) δ 167.6, 156.1 (2 C), 129.2, 118.4,
[M+H] : 280.1907, found 280.1915.
1
113.5 mg (0.406 mmol, 45%) pale yellow oil. R
f
0.30 (hexanes/EtOAc 1/1). H NMR (300 MHz, CDCl
3
3
1
.78 (s, 6H), 3.06 – 2.98 (m, 2H), 1.55 (s, 9H), 1.48 – 1.37 (m, 2H), 0.56 (t, J = 7.4 Hz, 3H). 13C NMR (101 MHz, CDCl
3
+
03.9 (2 C), 57.0, 55.8 (2 C), 48.8, 29.0 (3 C), 24.7, 11.3. HRMS (ES-MS): m/z calculated for C16
H
26NO
3
7-Methoxy-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (6).
Benzoazepinone 4a (93 mg, 0.376 mmol) was dissolved in 4 ml trifluoroacetic acid and heated under reflux conditions for 13 h. TFA was removed under
reduced pressure and brown oil was purified by flash chromatography (hexanes/EtOAc 2/1 to EtOAc) on deactivated silica (pretreated with 10% Et N in
3
hexanes) to give 61.8 mg (0.323 mmol, 86%) of compound 10 as pale beige solid.
Analytical data match to the reported data.8a
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