G.-H. Lu et al. / Chinese Chemical Letters 25 (2014) 61–64
63
C55CH); 13C NMR (100 MHz, CDCl3):
d
17.70 (CH3CHCH3), 19.00
3.83 (br, 4H, OCH3 + CHNH), 4.94 (s, 2H, CH2O), 7.23 (d, 1H,
J = 6.4 Hz, PhH), 7.35–7.47 (m, 3H, PhH), 7.63 (d, 1H, J = 7.4 Hz,
C55CH), 8.19 (br, 1H, CHNH), 10.28(br, 1H, NHO); 13C NMR
(CH3CHCH3), 22.66 (CH3CO), 31.02 (CH3CHCH3), 51.71 (COOCH3),
57.40 (NCH), 62.07 (OCH3), 65.17 (COCHCO), 109.57 (C55CH),
128.04, 128.16, 128.53, 131.22, 132.08, 134.31 (6C, C6H4), 160.59
(C55CH), 167.93, 171.27, 171.93, 187.87 (4C, 4ꢁCO); MS m/z (%):
363(0.5), 205(4), 190(40), 145(19); Anal. Calcd. for C21H25NO6: C,
65.10; H, 6.50; N, 3.62; Found: C, 65.26; H, 6.66; N, 3.57.
(100 MHz, CDCl3):
d 11.36 (CH3CNH), 15.75 (CH3CHCH3), 19.40
(CH3CHCH3), 29.88 (CH3CHCH3), 51.77 (COOCH3), 62.07 (OCH3),
62.20 (CHNH), 75.86 (CH2O), 97.91 (COCCO), 110.02 (C55CH),
128.15, 128.60, 129.08, 131.38, 132.51, 134.39 (6C, C6H4), 160.22
(C55CH), 160.43 (CNH), 167.80, 172.49, 187.43 (3C, 3ꢁCO); MS m/z
(%): 279(2), 190(65), 161(38), 140(65); Anal. Calcd. for
6c: Yellow viscous liquid, yield: 45%; IR (KBr, cm–1):
3067, 2963, 2878, 1738, 1630, 1537, 1456, 1255, 1205, 1143; 1H
NMR (400 MHz, CDCl3): 0.82–0.94 (m, 6H, CH3CH2 + CH3CH),
n 3367,
d
C
21H26N2O6: C, 62.67; H, 6.51; N, 6.96; Found: C, 63.26; H, 6.50;
N, 6.85.
9c: Yellow viscous liquid, yield: 41%; IR (KBr, cmꢀ1):
2960, 2868, 1709, 1679, 1634, 1568, 1431, 1257, 1130, 1110; 1H
NMR (400 MHz, CDCl3): 0.76–1.01 (m, 6H, CH3CH2 + CH3CH),
1.07–1.42 (m, 2H, CH3CH2), 1.84–1.99 (m, 1H, CH3CH), 2.03 (d, 3H,
J = 4.4 Hz, CH3CO), 3.71 (s, 3H, COOCH3), 3.84 (s, 3H, OCH3), 4.63,
4.74 (dd, dd, 1H, J = 8.7, 5.0, 9.1, 3.8 Hz, NCH), 5.01–5.12 (m, 2H,
PhCH2), 6.00 (dd, 1H, J = 30.2, 8.6 Hz, COCHCO), 7.14–7.20 (m, 1H,
PhH), 7.31–7.38 (m, 2H, PhH), 7.38–7.44 (m, 1H, PhH), 7.59 (s, 1H,
n
3207,
d
1.23–1.48(m, 2H, CH3CH2), 1.92–1.98 (m, 1H, CH3CH), 2.39 (d, 3H,
J = 3.9 Hz, CH3CNH), 3.69 (s, 3H, COOCH3), 3.82 (s, 3H, OCH3), 3.88–
3.95 (m, 1H, CHNH), 4.94 (s, 2H, CH2O), 7.22 (d, 1H, J = 7.4 Hz, PhH),
7.34–7.40 (m, 2H, PhH), 7.40–7.46 (m, 1H, PhH), 7.62 (s, 1H, C55CH),
8.06 (br, 1H, CHNH), 11.48 (br, 1H, NHO); 13C NMR (100 MHz,
C55CH); 13C NMR (100 MHz, CDCl3):
d 11.72 (CH3CH2), 15.45
(CH3CH), 22.76 (CH3CO), 26.16 (CH3CH2), 37.55 (CH3CH), 51.83
(COOCH3), 55.66 (NCH), 62.16 (OCH3), 65.43 (COCHCO), 109.66
(C55CH), 128.14, 128.26, 128.54, 131.26, 132.02, 134.24(6C, C6H4),
160.59 (C55CH), 168.06, 171.35, 171.91, 187.83 (4C, 4ꢁCO); MS m/z
(%): 377(1), 205(5), 190(40), 145(25); Anal. Calcd. for C22H27NO6:
C, 65.82; H, 6.78; N, 3.49; Found: C, 65.58; H, 6.86; N, 3.37.
CDCl3):
d 11.20 (CH3CNH), 11.81 (CH3CH2), 15.52 (CH3CH), 26.68
(CH3CH2), 36.72 (CH3CH), 51.59 (COOCH3), 60.62 (CHNH), 61.91
(OCH3), 75.66 (CH2O), 98.24 (COCCO), 109.86 (C55CH), 127.95,
128.39, 128.99, 131.33, 132.53, 134.59 (6C, C6H4), 160.04 (CNH),
160.29 (C55CH), 167.76, 172.73, 187.13 (3C, 3ꢁCO); MS m/z (%):
416(M+, 1), 205(23), 190(60), 140(100); Anal. Calcd. for
6d: Yellow viscous liquid, yield: 55%; IR (KBr, cmꢀ1):
3063, 2948, 2844, 1741, 1703, 1634, 1541, 1495, 1434, 1253, 1130;
1H NMR (400 MHz, CDCl3)
: 1.98 (s, 3H, CH3CO), 3.11 (ddd, 2H,
n 3305,
d
J = 30.4, 13.8, 5.7 Hz, PhCH2), 3.69 (s, 3H, COOCH3), 3.82 (s, 3H,
OCH3), 4.90 (dt, 1H, J = 7.7, 5.6 Hz, NCH), 5.06 (s, 2H, PhCH2), 5.95
(d, 1H, J = 7.6 Hz, COCHCO), 7.00–7.03 (m, 2H, PhH), 7.18 (d, 1H,
J = 6.4 Hz, PhH), 7.23–7.26 (m, 3H, PhH), 7.31–7.40(m, 3H, PhH),
C
22H28N2O6: C, 63.45; H, 6.78; N, 6.73; Found: C, 63.56; H, 6.86;
N, 6.57.
9d: Yellow viscous liquid, yield: 41%; IR (KBr, cmꢀ1):
2923, 2843, 1704, 1633, 1567, 1431, 1363, 1256, 1130, 1110; 1H
NMR (400 MHz, CDCl3): 2.35 (d, 3H, J = 2.8 Hz, CH3CNH), 2.66–
n
3245,
7.59 (s, 1H, C55CH); 13C NMR (100 MHz, CDCl3):
d
22.70 (CH3CO),
d
37.60 (PhCH2), 51.75 (COOCH3), 53.53 (NCH), 62.07 (OCH3), 65.39
(COCHCO), 109.67 (C55CH), 127.02, 128.09, 128.27, 128.56, 128.77,
129.32, 131.29, 132.26, 134.27, 136.24 (12C, C6H5 + C6H4), 160.62
(C55CH), 167.94, 170.69, 171.57, 187.95 (4C, 4ꢁCO); MS m/z (%):
411(1), 205(45), 190(62), 145(76); Anal. Calcd. for C25H25NO6: C,
68.95; H, 5.79; N, 3.22; Found: C, 68.78; H, 5.86; N, 3.27.
2.82 (m, 1H, PhCH2), 3.24 (dd, 1H, J = 13.9, 3.6 Hz, PhCH2), 3.66–
3.71 (m, 3H, COOCH3), 3.81 (d, 3H, J = 8.4 Hz, OCH3), 4.05–4.14 (m,
1H, CHNH), 4.92 (s, 2H, CH2O), 5.76 (br, 1H, CHNH), 7.19–7.47 (m,
9H, PhH), 7.62 (s, 1H, C55CH), 7.71 (m, 1H, NHO); 13C NMR
(100 MHz, CDCl3):
d 11.35 (CH3CNH), 38.39 (PhCH2), 51.80
(COOCH3), 59.01 (CHNH), 62.08 (OCH3), 76.31 (CH2O), 96.37
(COCCO), 109.89 (C55CH), 126.84, 128.17, 128.57, 128.85, 129.34,
129.93, 131.54, 132.81, 133.95, 136.86 (12C, C6H5 + C6H4), 160.43
(C55CH), 161.75 (CNH), 167.86, 172.10, 189.37 (3C, 3ꢁCO); MS m/z
(%): 230(29), 190(53), 161(32), 139(100); Anal. Calcd. for
9a: Yellow viscous liquid, yield: 35%; IR (KBr, cm–1):
2923, 2852, 1704, 1633, 1565, 1431, 1256, 1129, 1109; 1H NMR
(400 MHz, CDCl3): 1.37 (dd, 3H, J = 6.9, 4.5 Hz, CH3CH), 2.41 (s,
n 3268,
d
3H, CH3CNH), 3.69 (s, 3H, COOCH3), 3.82 (s, 3H, OCH3), 3.93–4.02
(m, 1H, CHNH), 4.93 (s, 2H, CH2O), 5.59 (br, 1H, CHNH), 7.22 (d, 1H,
J = 7.3 Hz, PhH), 7.36–7.45 (m, 3H, PhH), 7.62 (s, 1H, C55CH),
7.78(br, 1H, NHO); 13C NMR (100 MHz, CDCl3):
d 11.31 (CH3CNH),
C
25H26N2O6: C, 66.66; H, 5.82; N, 6.22; Found: C, 66.55; H, 5.96;
N, 6.27.
The targeted compounds were evaluated for fungicidal activity
17.62 (CH3CH), 51.63 (COOCH3), 53.02 (CHNH), 62.04 (OCH3),
75.93 (CH2O), 96.18 (COCCO), 109.83 (C55CH), 128.10, 128.60,
129.16, 131.41, 132.63, 134.26 (6C, C6H4), 160.22 (C55CH), 160.36
(CNH), 167.81, 172.08, 189.66 (3C, 3ꢁCO); MS m/z (%):
374[M+](1), 205(20), 190(80), 145(60); Anal. Calcd. for
against R. solani, B. cinerea and F. graminearum at the concentration
of 100 mg/L according to the method reported in the literature
[13]. The results were summarized in Table 1. These compounds
showed fungicidal activity at different degree. Most compounds
exhibited good activity against R. solani, among them the
inhibitory rates of compounds 9b, 9c and 9d reached 65.2%,
58.5% and 56.1%, respectively, obviously superior to that of the lead
compound TeA, which demonstrated an inhibitory rate of only
9.0%. As a whole the oxime ether derivatives 9a–9d showed better
bioactivity than the benzyl derivatives 6a–6d. Compound 9d with
a benzyl group at the 5-position of pyrrolidine-2,4-dione exhibited
better bioactivity than other compounds 9a–9c.
C
19H22N2O6: C, 60.95; H, 5.92; N, 7.48; Found: C, 60.76; H,
5.86; N, 7.57.
9b: White powder, yield: 50%, mp 127.2–128.5 8C; IR (KBr,
cmꢀ1):
n
3189, 2955, 2874, 1707, 1679, 1631, 1567, 1487, 1253,
1128, 1105; 1H NMR (400 MHz, CDCl3):
d
0.86 (dd, 3H, J = 5.8,
2.4 Hz, CH3CHCH3), 1.04 (dd, 3H, J = 6.8, 3.1 Hz, CH3CHCH3), 2.21
(br, 1H, CH3CHCH3), 2.39 (s, 3H, CH3CNH), 3.69 (s, 3H, COOCH3),
Table 1
Fungicidal activity of the target compounds against R. solani, B. cinerea and F. gramineaum (100 mg/L, Inhibitory %).a
Compd.
R. solani
B. cinerea
F. graminearum
Compd.
R. solani
B. cinerea
F. graminearum
6a
38.3 ꢃ 1.5
20.0 ꢃ 0.8
25.5 ꢃ 1.0
38.7 ꢃ 1.2
9.0 ꢃ 0.5
4.7 ꢃ 0.7
8.7 ꢃ 0.9
7.8 ꢃ 1.3
10.3 ꢃ 0.7
20.3 ꢃ 1.1
43.2 ꢃ 1.1
15.2 ꢃ 0.7
18.0 ꢃ 0.8
33.6 ꢃ 1.7
8.9 ꢃ 0.2
9a
9b
9c
9d
49.8 ꢃ 0.9
65.2 ꢃ 0.8
58.5 ꢃ 1.2
56.1 ꢃ 0.7
12.4 ꢃ 1.4
20.2 ꢃ 1.2
25.4 ꢃ 1.0
58.6 ꢃ 1.7
21.5 ꢃ 1.0
7.9 ꢃ 0.6
6b
6c
32.2 ꢃ 1.5
38.8 ꢃ 1.4
6d
TeAb
a
Values are the mean ꢃ S.D. of three replicates.
b
Tenuazonic acid (5-sec-butyl-3-(1-hydroxyethylidene)pyrrolidine-2,4-dione).