Chapter 3
Synthesis and Herbicidal Activity of Sultamsulfonamides 1
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1
1
Kenzi Makino , Katsushi Morimoto , Shigeaki Akiyama , Hideaki Suzuki , Koichi Suzuki , Tsutomu Nawamaki, and Shigeomi Watanabe 2
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2
1
Central Research Institute, Nissan Chemical Industries Ltd., Tsuboi-cho 722-1, Funabashi, Chiba 274, Japan Research Station of Biological Science, Nissan Chemical Industries Ltd., Shiraoka 1470, Saitama 349-02, Japan
Downloaded by TUFTS UNIV on June 3, 2018 | https://pubs.acs.org Publication Date: May 5, 1995 | doi: 10.1021/bk-1995-0584.ch003
2
The regioselectively methylated 1-thia-2-azacyclopentane-1,1 -dioxides (propanesultams) and 1-thia-2-azacyclohexane-1,1 -dioxides (butanesultams) and 3-halomethylpropanesultams were synthesized, and converted into 5-phenyl-1-(sultam-N-sulfonyl -carbamoyl)pyrazolines 1 as a new ALS inhibitor. Some of these showed strong herbicidal actvity against broad-leaved weeds without phytotoxicity to wheat. In this chapter, syntheses of mono-, di- and trimethylpropanesultams, mono- and dimethyl -butanesultams and halomethylpropanesultams, and furthermore, synthetic procedure and herbicidal activity of 1 will be discussed. Propane- and butanesultams have been utilized as building blocks in the synthesis of new pharmaceuticals, as for example in the case of anticonvulsants, a PGE2 analog, and antihistamines-Hi (1-3). Since this was not the case in the field of agro chemicals, we looked for opportunities for their use in the synthesis of new herbicides. On the other hand, Wellinga et. al. reported the synthesis of herbicidally active benzenesulfonamides incorporating a pyrazoline moiety (4). On the basis of reported structural requirements for known inhibitors, we suspected that these compounds were ALS inhibitors. In our continuing studies directed toward new ALS inhibitors, we incorporated both the sultam (cyclic sulfonamide) and pyrazoline moieties into the same molecule, and discovered a new class of herbicidally active sultamsulfonamides 1 (Figure 1) (5). Wefirstdescribe the synthesis of propane- and butanesultams in detail (Figure 2). In support of structure-activity studies in the sultamsulfonamide series, we elaborated facile methods for the synthesis of mono-, di- and trimethylpropanesultams 7a-d, mono- and dimethyl- butanesultams lla-c, and 3-halomethylpropanesultams 23a-d, not obtainable by reported methods (6-8). Second, we describe the synthesis of 5phenylpyrazolines 32a,b, and furthermore, the synthesis and herbicidal activity of sultamsulfonamides 1. 0097-6156/95/0584-0026S12.00/0 © 1995 American Chemical Society
Baker et al.; Synthesis and Chemistry of Agrochemicals IV ACS Symposium Series; American Chemical Society: Washington, DC, 1995.
3.
MAKINO ET AL.
Synthesis & Herbicidal Activity of Sultamsulfonamides
R Downloaded by TUFTS UNIV on June 3, 2018 | https://pubs.acs.org Publication Date: May 5, 1995 | doi: 10.1021/bk-1995-0584.ch003
1
/
N
N
M
e
^ ~ ? ° 2 / ^ / (CH ) N-S0 NHCN V / 1 X V ^ R S v ' V ^ R H^T 2
n
3
2
2
]
0
2
1
Sultam Moiety
1
1
2
R ,R = H, Me, R =H,Me,CH X (X= F, CI, Br, I) n=2or3 Y= H, Me Z= H, F, CI, Me, OMe
Z
1
5-phenylpyrazoline Moiety
Figure 1. Sultamsulfonamides 1
R
1
^"^soz (CH ) 2
r
NH =
n
Me
Y-so 1
[
(Me)
2
m
2
n=2or3
Me
2
^sp
2
NH
I
NH
N—so
2
cH X 2
2
