Molecules 2019, 24, 2783
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3-Isopropoxy-4-[(4-nitro-3-propoxy-benzoyl)amino]benzamide (14f): Light yellow solid, 24 mg, 40% overall
yield, 95% purity by HPLC. 1H NMR (DMSO-d6, 270 MHz):
9.66 (br s, 1 H), 8.01(d, J = 8.4 Hz, 1 H),
δ
7.98 (br s, 1 H), 7.91 (d, J = 8.2 Hz, 1 H), 7.78 (d, J = 1.4 Hz, 1 H), 7.60 (dd, J = 8.2, 1.4 Hz, 1 H), 7.58
(d, J = 1.5 Hz, 1 H), 7.52 (dd, J = 8.4, 1.6 Hz, 1 H), 7.37 (br s, 1 H), 4.70 (sep, J = 6.2 Hz, 1 H), 4.23
(t, J = 6.4 Hz, 2 H), 1.83–1.71 (m, 2 H), 1.32 (d, J = 5.7 Hz, 6 H), 0.99 (t, J = 7.4 Hz, 3 H). 13C NMR
(DMSO-d6, 150 MHz):
δ 167.2, 163.6, 151.0, 148.9, 141.2, 139.5, 131.5, 130.2, 125.1, 123.1, 119.9, 119.4,
114.1, 113.1, 71.2, 70.8, 21.8, 21.7, 10.2. MALDI-TOF (m/z): [M + Na]+ calcd for C20H23N3NaO6: 424.15,
found 424.62.
4-[(3-Butoxy-4-nitrobenzoyl)amino]-3-isopropoxybenzamide (14h): Light yellow solid, 28 mg, 45% overall
yield based on the loading of Fmoc-Rink amide resin, 96% purity by HPLC, m.p. 213–214 ◦C. 1H NMR
(DMSO-d6, 270 MHz):
δ 9.65 (br s, 1 H), 8.01 (d, J = 8.4 Hz, 1 H), 7.99 (br s, 1 H), 7.92 (d, J = 8.4 Hz, 1 H),
7.79 (br s, 1 H), 7.59 (d, J = 8.3 Hz, 1 H), 7.58 (br s, 1 H), 7.52 (d, J = 8.4 Hz, 1 H), 7.37 (br s, 1 H), 4.70
(sep, J = 5.9 Hz, 1 H), 4.27 (t, J = 6.4 Hz, 2 H), 1.79–1.68 (m, 2 H), 1.51–1.37 (m, 2 H), 1.32 (d, J = 5.9 Hz,
6 H), 0.93 (t, J = 7.4 Hz, 3 H). 13C NMR (DMSO-d6, 150 MHz):
δ 167.2, 163.5, 150.9, 148.9, 141.2, 139.4,
131.5, 130.2, 125.0, 122.9, 119.9, 119.4, 114.0, 113.0, 71.2, 69.1, 30.3, 21.8, 18.5, 13.5. MALDI-TOF (m/z):
[M + Na]+ calcd for C21H25N3NaO6: 438.16, found 438.51.
4-[(3-Isobutoxy-4-nitrobenzoyl)amino]-3-isopropoxybenzamide (14i): Light yellow solid, 31 mg, 48% overall
yield, 93% purity by HPLC. 1H NMR (DMSO-d6, 270 MHz):
δ 9.66 (br s, 1 H), 8.02 (d, J = 8.4 Hz, 1 H),
7.99 (br s, 1 H), 7.92 (d, J = 8.2 Hz, 1 H), 7.77 (br s, 1 H), 7.59 (d, J = 8.3 Hz, 1 H), 7.58 (br s, 1 H), 7.52
(d, J = 8.4 Hz, 1 H), 7.36 (br s, 1 H), 4.70 (sep, J = 5.9 Hz, 1 H), 4.04 (d, J = 6.4 Hz, 2 H), 2.11–2.02 (m,
1 H), 1.32 (d, J = 5.7 Hz, 6 H), 0.99 (d, J = 6.7 Hz, 6 H). 13C NMR (DMSO-d6, 150 MHz):
δ 167.2, 163.5,
151.0, 148.9, 141.1, 139.5, 131.5, 130.2, 125.1, 123.0, 119.9, 119.4, 114.0, 113.0, 75.2, 71.2, 27.6, 21.8, 18.7.
MALDI-TOF (m/z): [M + Na]+ calcd for C21H25N3NaO6: 438.16, found 438.95.
3-Butoxy-4-[(4-nitro-3-propoxybenzoyl)amino]benzamide (14k): Light yellow solid, 23 mg, 37% overall
yield, >99% purity by HPLC. 1H NMR (DMSO-d6, 270 MHz):
δ 9.75 (br s, 1 H), 8.01 (d, J = 8.4 Hz,
1 H), 7.99 (br s, 1 H), 7.85 (d, J = 8.2 Hz, 1 H), 7.80 (d, J = 1.2 Hz, 1 H), 7.60 (dd, J = 8.4, 1.4 Hz, 1 H),
7.58 (d, J = 1.4 Hz, 1 H), 7.52 (dd, J = 8.4, 1.5 Hz, 1 H), 7.37 (br s, 1 H), 4.22 (t, J = 6.4 Hz, 2 H), 4.09
(t, J = 6.4 Hz, 2 H), 1.84–1.70 (m, 4 H), 1.52–1.38 (m, 2 H), 0.99 (t, J = 7.4 Hz, 3 H), 0.91 (t, J = 7.4 Hz,
3 H). 13C NMR (DMSO-d6, 150 MHz):
δ 167.2, 163.5, 150.9, 150.4, 141.2, 139.4, 131.8, 129.2, 125.0, 123.3,
119.8, 119.5, 114.0, 111.4, 70.8, 68.1, 30.7, 21.8, 18.7, 13.7, 10.2. MALDI-TOF (m/z): [M + Na]+ calcd for
C21H25N3NaO6: 438.16, found 438.75.
3-Butoxy-4-[(3-isopropoxy-4-nitrobenzoyl)amino]benzamide (14l): Light yellow solid, 25 mg, 40% overall
yield based on the loading of Fmoc-Rink amide resin, >99% purity by HPLC, m.p. 233–235 ◦C. 1H
NMR (DMSO-d6, 270 MHz):
δ 9.73 (br s, 1 H), 7.99 (br s, 1 H), 7.97 (d, J = 8.4 Hz, 1 H), 7.86 (d, J = 8.2 Hz,
1 H), 7.81 (d, J = 1.2 Hz, 1 H), 7.59 (dd, J = 8.2, 1.2 Hz, 1 H), 7.58 (d, J = 1.4 Hz, 1 H), 7.52 (dd, J = 8.3,
1.4 Hz, 1 H), 7.37 (br s, 1 H), 4.94 (sep, J = 5.9 Hz, 1 H), 4.09 (t, J = 6.2 Hz, 2 H), 1.80–1.70 (m, 2 H),
1.52–1.38 (m, 2 H), 1.33 (d, J = 6.2 Hz, 6 H), 0.91 (t, J = 7.4 Hz, 3 H). 13C NMR (DMSO-d6, 150 MHz):
δ
167.2, 163.5, 150.4, 149.7, 142.3, 139.2, 131.7, 129.2, 124.9, 123.3, 119.7, 119.6, 115.1, 111.4, 72.5, 68.2, 30.7,
21.5, 18.7, 13.7. MALDI-TOF (m/z): [M + H]+ calcd for C21H26N3O6: 416.18, found 416.56.
3-Butoxy-4-[(3-butoxy-4-nitrobenzoyl)amino]benzamide (14m): Light yellow solid, 20 mg, 31% overall
yield based on the loading of Fmoc-Rink amide resin, 92% purity by HPLC, m.p. 249–251 ◦C. 1H NMR
(DMSO-d6, 270 MHz):
δ 9.74 (br s, 1 H), 8.00 (d, J = 8.4 Hz, 1 H), 7.99 (br s, 1 H), 7.86 (d, J = 8.4 Hz,
1 H), 7.80 (d, J = 1.2 Hz, 1 H), 7.60 (dd, J = 8.4, 1.4 Hz, 1 H), 7.58 (br s, 1 H), 7.52 (dd, J = 8.3, 1.4 Hz,
1 H), 7.37 (br s, 1 H), 4.26 (t, J = 6.2 Hz, 2 H), 4.09 (t, J = 6.2 Hz, 2 H), 1.80–1.69 (m, 4 H), 1.52–1.37 (m,
4 H), 0.94 (t, J = 7.2 Hz, 3 H), 0.91 (t, J = 7.3 Hz, 3 H). 13C NMR (DMSO-d6, 68 MHz):
δ 167.8, 164.1,
151.5, 151.0, 141.8, 140.0, 132.3, 129.8, 125.6, 123.9, 120.3, 120.1, 114.5, 112.0, 69.7, 68.7, 31.2, 30.9, 19.3,
19.1, 14.3, 14.1. MALDI-TOF (m/z): [M + Na]+ calcd for C22H27N3NaO6: 452.18, found 452.56.