Studies of the New Herbicide KIH-6127
J. Agric. Food Chem., Vol. 45, No. 7, 1997 2779
Ta ble 2. P h ysicoch em ica l P r op er ties a n d NMR Da ta for Com p ou n d s 1-20
compd no.
mp (°C)
nD20
[1H]NMR δ (ppm)
1
2
4
106-107
59-60
2.17 (s, 3H), 3.76 (s, 3H), 3.82 (s, 6H), 3.96 (s, 3H), 5.73 (s, 1H), 7.16-7.50 (m, 3H)
2.20 (s, 3H), 3.65 (s, 3H), 3.69 (s, 3H), 3.83 (s, 6H), 5.73 (s, 1H), 6.90-7.70 (m, 3H)
1.26 (t, J ) 7 Hz, 3H), 2.17 (s, 3H), 3.79 (s, 3H), 3.83 (s, 6H), 4.23 (q, J ) 7 Hz, 2H), 5.73 (s, 1H),
93-95
7
.00-7.67 (m, 3H)
1.07 (t, J ) 6 Hz, 3H), 2.20 (s, 3H), 3.57 (s, 3H), 3.76 (s, 6H), 3.97 (q, J ) 6 Hz, 2H), 5.70 (s, 1H),
.85-7.67 (m, 3H)
1.00 (t, J ) 7 Hz, 3H), 1.70 (q, J ) 7 Hz, 2H), 2.23 (s, 3H), 3.73 (s, 3H), 3.83 (s, 6H), 4.13
t, J ) 7 Hz, 2H), 5.73 (s, 1H), 7.00-7.83 (m, 3H)
0.83 (t, J ) 7 Hz, 3H), 1.57 (q, J ) 7 Hz, 2H), 2.20 (s, 3H), 3.53 (s, 3H), 3.73 (s, 6H), 3.83
t, J ) 7 Hz, 2H), 5.72 (s, 1H), 6.92-7.67 (m, 3H)
2.20 (s, 3H), 3.75 (s, 3H), 3.80 (s, 6H), 3.50-4.0 (m, 2H), 4.34 (t, J ) 6 Hz, 2H), 5.80 (s, 1H),
.16-7.67 (m, 3H)
2.23 (s, 3H), 3.60 (t, J ) 6 Hz, 2H), 3.60 (s, 3H), 3.77 (s, 6H), 4.13 (t, J ) 6 Hz, 2H), 5.73 (s, 1H),
.85-7.70 (m, 3H)
2.20 (s, 3H), 3.66 (s, 3H), 3.79 (s, 6H), 4.60 (q, J ) 6 Hz, J ) 2 Hz, 2H), 5.0-5.15 (m, 1H),
.30 (q, J ) 10 Hz, J ) 2 Hz, 1H), 5.69 (s, 1H), 5.75-6.15 (m, 1H), 7.00-7.50 (m, 3H)
5
6
7
8
9
68-70
73-76
6
(
NM
(
1.5540
7
NMa
NM
6
1
1
0
1
76-78
5
2.17 (s, 3H), 3.53 (s, 3H), 3.70 (s, 6H), 4.33 (q, J ) 8 Hz, J ) 2 Hz, 2H),
4
6
.90-5.05 (m, 1H), 5.20 (q, J ) 10 Hz, J ) 2 Hz, 1H), 5.72 (s, 1H), 5.53-6.23 (m, 3H),
.89-7.65 (m, 3H)
1
1
1
1
2
3
4
5
1.5374
0.8-2.2, (m, 7H), 2.45 (s, 3H), 4.10 (s, 3H), 4.25 (s, 6H), 4.65 (t, J ) 5 Hz, 2H), 6.35 (s, 1H),
7
.7-8.1 (m, 3H)
2.20 (s, 3H), 3.38 (s, 3H), 3.50 (s, 6H), 3.50-4.17 (m, 2H), 4.20-4.50 (m, 2H), 4.67-5.00 (m, 2H),
.50 (s, 1H), 6.85-7.50 (m, 3H)
2.00 (s, 3H), 3.43 (s, 3H), 3.57 (s, 6H), 4.30 (q, J ) 8 Hz, J ) 18 Hz), 5.50 (s, 1H),
.83-7.50 (m, 3H)
2.25 (s, 3H), 3.79 (s, 3H), 3.83 (s, 6H), 4.69 (t, J ) 8 Hz), 5.83 (s, 1H), 6.00-6.40 (m, 1H),
.15-7.85 (m, 3H)
90-92
63-64
5
6
1.5579
1.5510
7
1
1
1
6
7
8
131-132
54-56
2.15 (s, 3H), 3.66 (s, 3H), 3.76 (s, 6H), 5.69 (s, 1H), 7.03-7.66 (m, 3H), 9.00 (broad, 1H)
2.16 (s, 3H), 2.26 (s, 3H), 3.66 (s, 3H), 3.76 (s, 6H), 5.73 (s, 1H), 7.080-7.73 (m, 3H)
2.30 (s, 3H), 3.77 (s, 3H), 3.87 (s, 6H), 4.75 (s, 1H), 5.40-5.63 (m, 1H), 5.83 (s, 1H),
7
.16-7.84 (m, 3H)
2.16 (s, 3H), 3.67 (s, 3H), 3.87 (s, 6H), 4.73 (s, 2H), 5.77 (s, 1H), 5.57-6.00 (m, 2H),
.15-7.73 (m, 3H)
2.16 (s, 3H), 3.53 (s, 3H), 3.63 (s, 6H), 5.10 (s, 2H), 5.67 (s, 1H), 6.83-7.83 (m, 8H)
1
2
9
0
1.5576
1.5689
7
a
NM, not measured due to viscous oil.
F igu r e 3. Synthesis of 16 and further cyclization reaction of 16.
dissolved. During additional heating for 8 h, a white precipi-
tate was gradually observed in the reaction solvent. The
reaction mixture was then cooled to room temperature, and
the precipitate was filtered and washed with isopropyl ether
test, an aqueous solution (10 mL) of a wettable powder of the
chemicals at the desired dosages was shaken and poured into
the pots individually. The test pots were placed in a green-
house and maintained under the following conditions through-
out the experiments: room temperature was maintained at
20-35 °C and water temperature was maintained at 15-30
°C, under natural daylight conditions.
1
to give 23 (6.5 g; 45.4% yield); mp 168-170 °C. [ H]NMR δ:
2
.53 (s, 1H), 3.73 (s, 1H), 5.70 (s, 1H), 7.40-8.07 (m, 3H) ppm.
F or m u la tion of Test Ch em ica ls a n d P r ep a r a tion of
Test P ots. Each test compound was formulated as a 100 g
Eva lu a tion of Biologica l Activities. The herbicidal
symptoms of all test compounds were the same: stunting and
slight yellowing. These symptoms are typical for ALS inhibi-
tors (Shimizu et al., 1994). The results of the visual evaluation
scores based on these symptoms are well correlated empirically
to those based on dry weights. Therefore, we used an empirical
visual evaluation method focusing on the stunting symptom.
Three weeks after treatment (DAT 21), the herbicidal activity
and rice injury ratings were visually evaluated on a percent
scale, comparing the herbicidal symptoms of each observed pot
with two reference pots which indicated 0% () no control or
no crop injury) and 100% () completely killed). ED50 values
were calculated as the amounts of active ingredient per hectare
-
1
ai/kg wettable powder, containing Emalgen 810 (5.0 g kg
,
1
-octyl-4-polyoxoethyleneoxybenzene, Kao Ltd.), Demolon (5.0
-1
g kg , sodium polymethylnaphthalenesulfonic acid, Kao Ltd.),
Kunilite 250 (180 g kg , diatomaceous earth, Kunimine Ltd.),
Carplex No. 80 (60 g kg , silicon dioxide, Shionogi Co., Ltd.),
and Zeeklite (clay).
-1
-
1
The wettable powder was diluted with water to the desired
2
concentrations. Plastic pots (square; 100 cm in surface area)
were filled with paddy soil (clay loam soil: sand 45%, silt
3
1.1%, and clay 23.9%; organic matter 1.44%, pH 5.6), which
was collected locally from a paddy field in Kikugawa, J apan.
Unless otherwise noted, the same soil was used in this work.
Water was added up to 3 cm in depth to create flooded paddy
conditions. The level of flooding water was maintained
throughout the test period. Twenty seeds of E. oryzicola (Ec)
were seeded at a depth of 0.5 cm one day after puddling and
fertilization. A rice seeding (Oryza sativa, two-leaf growth
stage) (Or) was transplanted at a depth of 3 cm in the same
pot. One day after seeding for the pre-emergence test or when
Ec reached the three-leaf growth stage for the post-emergence
-
1
(g ai ha ) required for 50% of maximum injury to barnyard
grass or rice. For the QSAR analysis, the activity of each
chemical against barnyard grass and rice is expressed as I50
2
(I50 ) ED50/[MW × 10 ]), i.e., units of molar concentration of
-
1
active ingredient per are (M ai a ). QSAR equations were
carried out using pI50 (log[1/I50]; the logarithm of the reciprocal
-
1
of I50). These biological activities (ED50(Ec) in g ai ha , ED50
-
-
1
-1
(Or) in kg ai ha , and pI50 in mol ai a ) are cited in Table 1.