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under vacuum to give crude product which was puried by silica
gel column chromatography using petroleum ether/EtOAc as
eluent. BN-01 was isolated as a yellow solid (0.12 g, 18.1%), mp
148–151 ꢂC. 1H-NMR (400 MHz, CDCl3): d (ppm) 7.67 (d, J ¼
15.4 Hz, 1H), 7.61 (d, J ¼ 6.8 Hz, 2H), 7.36–7.19 (m, 4H), 7.15–
7.10 (m, 2H), 6.76 (d, J ¼ 8.3 Hz, 1H), 6.39 (d, J ¼ 15.4 Hz, 1H),
(E)-3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-N-(2-methoxyphenyl)
acrylamide (BN-04). BN-04 was isolated as a light yellow solid
(0.27 g, 37.1%), mp 115–116 ꢂC. 1H-NMR (400 MHz, DMSO-d6):
d (ppm) 10.00 (s, 1H), 7.61 (d, J ¼ 9.0 Hz, 2H), 7.45 (d, J ¼
15.6 Hz, 1H), 7.37 (dd, J ¼ 8.4 Hz, 1.6 Hz, 1H), 7.33 (d, J ¼ 1.6 Hz,
1H), 6.90 (d, J ¼ 9.0 Hz, 2H), 6.80 (d, J ¼ 8.4 Hz, 1H), 6.63 (d, J ¼
15.6 Hz, 1H), 6.45 (d, J ¼ 9.8 Hz, 1H), 5.82 (d, J ¼ 9.8 Hz, 1H),
3.73 (s, 3H), 1.40 (s, 6H). 13C NMR (150 MHz, CDCl3) d 164.1,
154.8, 147.8, 141.7, 131.3, 129.2, 128.0, 127.5, 126.0, 123.6,
121.8, 121.3, 121.2, 119.9, 118.7, 116.7, 109.8, 77.0, 55.7, 28.2.
ESI-MS m/z: 336.1 [M + H]+, 358.1 [M + Na]+, 671.3 [2M + H]+,
693.3 [2M + Na]+.
6.31 (d, J ¼ 9.8 Hz, 1H), 5.65 (d, J ¼ 9.8 Hz, 1H), 1.44 (s, 6H). 13
C
NMR (150 MHz, CDCl3) d 164.4, 154.9, 142.2, 138.2, 131.3, 129.1,
129.0, 127.3, 126.2, 124.2, 121.8, 121.3, 119.9, 118.1, 116.8, 77.7,
28.2. ESI-MS m/z: 306.1 [M + H]+, 328.1 [M + Na]+, 611.2 [2M +
H]+, 633.2 [2M + Na]+.
4.1.12 General procedure for the synthesis of BN-02, 04, 05,
07–10. To a solution of (E)-3-(2,2-dimethyl-2H-chromen-6-yl)
acrylic acid (0.5 g, 2.17 mmol), N,N-dimethylformamide (1
drop) in anhydrous dichloromethane (20 mL) were added thi-
onyl chloride (0.56 mL, 8.68 mmol). The reaction mixture was
heated to reux for 30 min. Aer cooling to room temperature,
the solvent was removed in vacuo, and the residue was dissolved
in anhydrous dichloromethane (5 mL). This intermediate was
taken to the next step without further purication. To a solution
of substituted aniline (3.5 mmol), triethylamine (1.5 mL, 10.8
mmol) in anhydrous dichloromethane (20 mL) were added
dropwise solution of (E)-3-(2,2-dimethyl-2H-chromen-6-yl)
acrylic chloride (2.2 mmol) in dichloromethane which was
prepared in the previous step at 0 ꢂC. The reaction mixture was
stirred at room temperature for 2 h. The reaction mixture was
poured into ice water (20 mL), and extracted with dichloro-
methane (2ꢃ 10 mL). The combined organic phase was
respectively washed with 10% HCl (3ꢃ 30 mL), 10% NaHCO3
(3ꢃ 30 mL), and brine (30 mL). The organic phase was dried
over sodium sulfate and concentrated under vacuum to give
crude product which was puried by silica gel column chro-
matography using petroleum ether/EtOAc as eluent.
(E)-3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-acrylate-phenyl ester
(BN-05). BN-05 was isolated as a white solid (0.25 g, 37.6%), mp
93–94 ꢂC. 1H-NMR (400 MHz, CDCl3): d (ppm) 7.77 (d, J ¼
15.9 Hz, 1H), 7.42–7.38 (m, 2H), 7.36 (dd, J ¼ 8.4 Hz, 2.1 Hz, 1H),
7.24–7.21 (m, 2H), 7.17–7.15 (m, 2H), 6.80 (d, J ¼ 8.4 Hz, 1H),
6.47 (d, J ¼ 15.9 Hz, 1H), 6.34 (d, J ¼ 9.9 Hz, 1H), 5.67 (d, J ¼
9.9 Hz, 1H), 1.46 (s, 6H). 13C NMR (150 MHz, CDCl3) d 165.7,
155.5, 150.9, 146.3, 131.4, 129.7, 129.4, 126.9, 126.4, 125.6,
121.7, 121.6, 121.4, 116.9, 114.4, 77.2, 28.3. ESI-MS m/z: 307.0 [M
+ H]+, 345.0 [M + Na]+, 635.7 [M + Na]+.
(E)-3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-1-(4-(4-hydroxyphenyl)-
piperazin-1-yl)prop-2-en-1-one (BN-07). BN-07 was isolated as a red
1
ꢂ
brown solid (0.04 g, 4.7%), mp 193–196 C. H-NMR (400 MHz,
DMSO-d6): d (ppm) 8.90 (s, 1H), 7.49–7.46 (m, 2H), 7.42 (d, J ¼
15.3 Hz, 1H), 7.13 (d, J ¼ 15.3 Hz, 1H), 6.84–6.81 (m, 2H), 6.76 (d, J
¼ 8.0 Hz, 1H), 6.67–6.65 (m, 2H), 6.42 (d, J ¼ 10.0 Hz, 1H), 5.81 (d,
J ¼ 10.0 Hz, 1H), 3.81 (s, 2H), 3.68 (s, 2H), 2.95 (s, 4H), 1.38 (s, 6H).
13C NMR (150 MHz, CDCl3) d 165.9, 155.5, 154.7, 146.3, 143.2,
131.3, 129.7, 129.0, 127.9, 125.9, 122.3, 121.8, 121.3, 118.2, 116.7,
114.4, 113.9, 77.0, 51.0, 49.9, 45.6, 40.0, 28.2. ESI-MS m/z: 391.2 [M
+ H]+, 781.3 [2M + H]+.
(E)-3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-N-(4-methoxyphenyl)-
acrylamide (BN-02). BN-02 was isolated as a yellow solid (0.22 g,
30.2%), mp 140-143 ꢂC. 1H-NMR (400 MHz, DMSO-d6): d (ppm)
10.00 (s, 1H), 7.61 (d, J ¼ 9.0 Hz, 2H), 7.45 (d, J ¼ 15.6 Hz, 1H),
7.36 (dd, J ¼ 8.3 Hz, 1.8 Hz, 1H), 7.33 (d, J ¼ 1.8 Hz, 1H), 6.90 (d, J
¼ 9.0 Hz, 2H), 6.80 (d, J ¼ 8.3 Hz, 1H), 6.63 (d, J ¼ 15.6 Hz, 1H),
6.45 (d, J ¼ 9.8 Hz, 1H), 5.82 (d, J ¼ 9.8 Hz, 1H), 3.73 (s, 3H), 1.39
(s, 6H). 13C NMR (150 MHz, CDCl3) d 164.3, 156.4, 154.8, 141.7,
131.4, 131.3, 129.1, 127.4, 126.1, 121.8, 121.7, 121.3, 118.3,
116.7, 114.2, 77.2, 55.5, 28.2. ESI-MS m/z: 671.3 [2M + H]+, 693.2
[2M + Na]+.
3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-N-phenyl-3-(phenylamino)-
propanamide (BN-08). BN-08 was isolated as a white solid (0.14 g,
16.2%), mp 143–146 ꢂC. 1H-NMR (400 MHz, CDCl3): d (ppm) 7.57
(m, 1H), 7.33 (d, J ¼ 7.6 Hz, 2H), 7.28 (d, J ¼ 7.6 Hz, 2H), 7.14–7.06
(m, 4H), 6.97 (d, J ¼ 1.9 Hz, 1H), 6.73–6.69 (m, 2H), 6.62 (d, J ¼
7.8 Hz, 2H), 6.23 (d, J ¼ 9.8 Hz, 1H), 5.58 (d, J ¼ 9.8 Hz, 1H), 4.85
(s, 1H), 4.76 (t, J ¼ 6.1 Hz, 1H), 2.8 (d, J ¼ 6.2 Hz, 2H), 1.40 (s, 6H).
13C NMR (150 MHz, CDCl3) d 169.0, 152.4, 146.4, 137.4, 134.1,
131.1, 129.2, 129.0, 126.8, 124.6, 124.2, 122.2, 121.5, 120.3, 118.5,
116.7, 114.4, 76.4, 55.4, 45.5, 28.1, 28.0. ESI-MS m/z: 399.2 [M +
H]+, 437.1 [M + K]+, 797.3 [2M + H]+.
3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-N-(4-methoxyphenyl)-3-
((4-methoxyphenyl)amino)propanamide (BN-09). BN-09 was iso-
lated as a white solid (0.08 g, 8.4%), mp 130–133 ꢂC.1H-NMR
(400 MHz, DMSO-d6): d (ppm) 9.70 (s, 1H), 7.43 (d, J ¼ 9.0 Hz,
2H), 7.12 (dd, J ¼ 8.2, 1.7 Hz, 1H), 7.06 (d, J ¼ 1.5 Hz, 1H), 6.84
(d, J ¼ 9.0 Hz, 2H), 6.64–6.62 (m, 3H), 6.49 (d, J ¼ 8.9 Hz, 2H),
6.33 (d, J ¼ 9.8 Hz, 1H), 5.74 (d, J ¼ 7.9 Hz, 1H), 5.59 (d, J ¼
9.8 Hz, 1H), 4.67 (q, J ¼ 14.4, 7.3 Hz, 1H), 3.70 (s, 3H), 3.58 (s,
3H), 2.72 (dd, J ¼ 14.2, 7.8 Hz, 1H), 2.58 (dd, J ¼ 14.2, 6.4 Hz,
1H), 1.32 (s, 6H). 13C NMR (150 MHz, CDCl3) d 169.0, 156.5,
153.0, 152.3, 140.3, 134.3, 131.0, 130.6, 126.8, 124.2, 122.2,
122.1, 121.4, 116.6, 116.2, 114.8, 114.1, 76.3, 56.6, 55.6, 55.5,
45.2, 28.1, 28.0. ESI-MS m/z: 459.2 [M + H]+.
3-(2,2-Dimethyl-2H-1-benzopyran-6-yl)-N-(3-methoxyphenyl)-3-
((3-methoxyphenyl)amino)propenamide (BN-10). BN-10 was iso-
lated as a white solid (0.22 g, 22.1%), mp 145–146 ꢂC. 1H-NMR
(400 MHz, CDCl3): d (ppm) 7.50 (1H, s), 7.18 (t, J ¼ 8.2 Hz, 1H),
7.09–7.07 (m, 2H), 7.04 (t, J ¼ 8.2 Hz, 1H), 6.97 (d, J ¼ 2.0 Hz,
1H), 6.80 (d, J ¼ 7.9 Hz, 1H), 6.71 (d, J ¼ 8.2 Hz, 1H), 6.63 (dd, J
¼ 8.2 Hz, 2.0 Hz, 1H), 6.29–6.22 (m, 3H), 6.18 (s, 1H), 5.58 (d, J
¼ 9.8 Hz, 1H), 4.74 (t, J ¼ 6.1 Hz, 1H), 3.72 (s, 3H), 3.69 (s, 3H),
2.81 (d, J ¼ 6.1 Hz, 2H), 1.40 (s, 6H). 13C NMR (150 MHz, CDCl3)
d 168.8, 160.6, 160.0, 152.5, 146.7, 138.5, 133.2, 131.1, 130.0,
129.6, 127.0, 124.4, 122.1, 121.5, 116.7, 112.4, 110.5, 108.0,
105.9, 104.7, 101.1, 76.6, 56.2, 55.3, 55.1, 45.0, 28.1, 28.0. ESI-
2506 | RSC Adv., 2019, 9, 2498–2508
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