6
N. Phan Thi Thanh et al. / Tetrahedron 76 (2020) 131481
chlorophenyl)-N-methylacetamide 1c (41.7 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 5-chloro-1-
methylindolin-2-one (2c) as white powder. 94% yield. NMR (1H,
13C), IR data agree with reported values [11l].
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 7-bromo-1-
methylindolin-2-one (2i) as yellow powder. 98% yield. 1H NMR
(500 MHz, CDCl3)
6.89e6.86 (m, 1H), 3.59 (s, 3H), 3.53 (s, 2H) ppm. 13C NMR
(125 MHz, CDCl3) 175.41, 142.25, 133.62, 127.30, 123.44, 102.21,
35.78, 29.75 ppm. IR (neat)
2943, 1716, 1462, 1332, 794 cmꢀ1
d
7.38 (d, J ¼ 8.03 Hz, 1H), 7.16 (d, J ¼ 8.03 Hz, 1H),
d
4.3.4. 5-Bromo-1-methylindolin-2-one (2d)
n
.
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(4-
bromophenyl)-N-methylacetamide 1d (41.7 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 5-bromo-1-
methylindolin-2-one (2d) as white powder. 93% yield. NMR (1H,
13C), IR data agree with reported values [10, 11l].
HRMS (DART) calcd for C9H8NOBr [MþH]þ: 225.9860 found:
225.9867.
4.3.10. 7-Iodo-1-methylindolin-2-one (2j)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(2-
Iodophenyl)-N-methylacetamide 1j (54.6 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 7-iodo-1-
methylindolin-2-one (2j) as yellow powder. 97% yield. 1H NMR
4.3.5. 5-Iodo-1-methylindolin-2-one (2e)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(4-
iodophenyl)-N-methylacetamide 1e (54.6 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 5-iodo-1-
methylindolin-2-one (2e) as white powder. 99% yield. 1H NMR
(500 MHz, CDCl3)
1.15 Hz, 1H), 6.73 (t, J ¼ 7.64 Hz, 1H), 3.58 (s, 3H), 3.49 (s, 2H) ppm.
13C NMR (125 MHz, CDCl3)
175.14, 145.89, 140.23, 127.48, 124.19,
d
7.67 (dd, J ¼ 8.03, 1.15 Hz, 1H), 7.18 (dd, J ¼ 7.64,
d
124.11, 71.97, 36.12, 29.54 ppm. IR (neat)
n 2942, 1706, 1455, 1333,
766 cmꢀ1. HRMS (DART) calcd for C10H11NO[MþH]þ: 273.9721
(500 MHz, CDCl3)
d
7.57 (d, J ¼ 8.41 Hz, 1H), 7.51 (s, 1H), 6.58 (d,
found: 273.9728.
J ¼ 8.41 Hz, 1H), 3.48 (s, 2H), 3.16 (s, 3H) ppm. 13C NMR (125 MHz,
CDCl3)
d
174.27, 144.76, 136.79, 133.13, 126.91, 110.14, 84.84, 35.42,
4.3.11. 1-Phenylindolin-2-one (2l)
26.18 ppm. IR (neat)
n
2935, 1696, 1364, 1100, 810 cmꢀ1. HRMS
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N,N-diphe-
nylacetamide 1l (47.5 mg, 0.2 mmol). The resulting mixture was
purified by silica gel column chromatography with EtOAc/n-Hexane
(1/3 (v/v)) to give 1-phenylindolin-2-one (2l) as white powder, 99%
yield. NMR (1H, 13C), IR data agree with reported values [10, 11l].
(DART) calcd for C9H8NOI [MþH]þ: 273.9722 found: 273.9728.
4.3.6. 5-Nitro-1-methylindolin-2-one (2f)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(4-
nitrophenyl)-N-methylacetamide 1f (43.8 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 5-nitro-1-
methylindolin-2-one (2f) as white powder. 94% yield. NMR (1H,
13C), IR data agree with reported values [11l].
4.3.12. 1-Ethylindolin-2-one (2m)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-ethyl-N-
phenylacetamide 1m (32.4 mg, 0.2 mmol). The resulting mixture
was purified by silica gel column chromatography with EtOAc/n-
Hexane (1/3 (v/v)) to give 1-ethylindolin-2-one (2m) as white
4.3.7. 1,6-Dimethylindolin-2-one (2ga), 1,4-dimethylindolin-2-one
(2gb)
powder. 94% yield. 1H NMR (500 MHz, CDCl3)
d
7.25 (dd, J ¼ 16.82,
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(3-
methylphenyl)-N-methylacetamide 1g (37.8 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 1,6-dimethylindolin-
2-one (2ga), 1,4-dimethylindolin-2-one (2gb) as yellow powder.
98% yield. NMR (1H, 13C), IR data agree with reported values
8.03 Hz, 2H), 7.01 (t, J ¼ 7.26 Hz, 1H), 6.83 (d, J ¼ 8.03 Hz, 1H), 3.75
(q, J ¼ 7.26 Hz, 2H), 3.49 (s, 2H), 1.25 (t, J ¼ 7.26 Hz, 3H) ppm. 13
C
NMR (125 MHz, CDCl3)
d 174.79, 144.05, 127.89, 124.85, 124.58,
122.20, 108.28, 35.94, 34.72, 12.76 ppm. IR (neat) n 2978, 1699, 1466,
1245, 749 cmꢀ1. HRMS (DART) calcd for C10H11NO [MþH]þ:
162.0914 found: 162.0928.
4.3.13. 1-Isopropylindolin-2-one (2n)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-isopropyl-
N-phenylacetamide 1n (35.2 mg, 0.2 mmol). The resulting mixture
was purified by silica gel column chromatography with EtOAc/n-
Hexane (1/3 (v/v)) to give 1-isopropylindolin-2-one (2n) as white
4.3.8. 7-Methoxy-1-methylindolin-2-one (2h)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(2-
methoxyphenyl)-N-methylacetamide 1h (35.6 mg, 0.2 mmol). The
resulting mixture was purified by silica gel column chromatog-
raphy with EtOAc/n-Hexane (1/3 (v/v)) to give 7-methoxy-1-
methylindolin-2-one (2h) as yellow powder. 93% yield. 1H NMR
powder. 91% yield. 1H NMR (500 MHz, CDCl3)
d 7.25e7.21 (m, 2H),
7.01e6.98 (m, 2H), 4.67 (seq, J ¼ 6.88 Hz, 1H), 3.48 (s, 2H), 1.46 (d,
J ¼ 6.88 Hz, 6H) ppm. 13C NMR (125 MHz, CDCl3)
d 174.79, 143.88,
(500 MHz, CDCl3)
1H), 3.48 (s, 2H), 3.48 (s, 3H) ppm. 13C NMR (125 MHz, CDCl3)
175.20, 145.37, 133.11, 125.97, 122.46, 117.07, 111.54, 55.67, 35.62,
28.50 ppm. IR (neat)
2978, 1694, 1467, 1253, 754 cmꢀ1. HRMS
d
6.98e6.95 (m, 1H), 6.86e6.84 (m, 2H), 3.85 (s,
127.60, 125.09, 124.64, 121.81, 109.92, 43.59, 36.03, 19.40 ppm. IR
(neat)
11H13NO [MþH]þ: 176.1071 found: 176.1074.
n
2973, 1709, 1485, 1246, 749 cmꢀ1. HRMS (DART) calcd for
d
C
n
(DART) calcd for C10H11NO2 [MþH]þ: 178.0863 found: 178.0868.
4.3.14. 1-Benzylindolin-2-one (2o)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-benzyl-N-
phenylacetamide (1o) (50.2 mg, 0.2 mmol). The resulting mixture
was purified by silica gel column chromatography with EtOAc/n-
Hexane (1/3 (v/v)) to give 1-benzylindolin-2-one (2o) as white
4.3.9. 7-Bromo-1-methylindolin-2-one (2i)
This compound was prepared according to the typical procedure
for intramolecular CeH insertion reaction of 2-diazo-N-(2-
bromophenyl)-N-methylacetamide 1i (45.2 mg, 0.2 mmol). The