Larvicidal and Fungicidal Activity of Compounds with

Chapter 25 Larvicidal and Fungicidal Activity of Compounds with Hydrazinecarboxamide and Diazenecarboxamide Moieties 1

1

Albert B. DeMilo , Stephen B. Haught , and Hugh D. Sisler

2

1

Insect Reproduction Laboratory, Agricultural Research Center, U.S. Department of Agriculture, Beltsville, MD 20705 Department of Botany, University of Maryland, College Park, MD 20742

Downloaded by UNIV LAVAL on May 9, 2016 | http://pubs.acs.org Publication Date: November 3, 1987 | doi: 10.1021/bk-1987-0355.ch025

2

Based on the effectiveness of N-(2,4-difluoro= phenyl)-2-(2-fluorophenyl)-hydrazinecarboxamide in house fly larvicidal tests, 53 analogs were synthesized and structure-activity relationships (SAR) defined. The most potent larvicide identified from this study was 2-(2-fluorophenyl)= -N-[2-(trifluoromethyl)phenyl]-hydrazinecarbox= amide. This compound caused > 90% mortality to early instars, when administered in a larval diet at a concentration of 1-5 ppm. As part of the SAR study, nine diazenecarboxamides were synthesized and evaluated. Activity of diazenecarboxamides paralleled that observed for corresponding hydra= zinecarboxamides. Three hydrazinecarboxamides and three diazenecarboxamides were highly (< 5.0 ppm) fungitoxic to one or more plant pathogens: Pyricularia oryzae, Botrytis cinerea, and Monilinia fructicola. SAR defined from fungicide tests appear to parallel those defined from larvicide tests. The most potent larvicides and fungicides possessed fluorine or fluorine-containing substituents on the benzene rings. Because of their ability to induce sterility in insects, hydrazine-derived compounds have long been of interest to us in our search for new reproduction inhibitors ( l_-4). In this context, we recently evalu = ated compound J., N-( 2 , 4-di f luoropheny 1 )-2-( 2-f luor o = phenyl)-hydrazinecarboxamide (Figure 1), and found that it inhibited oviposition in house flies (Musca domestica L.) when administered orally to adults. However, since infertility was accompanied by excessive adult mortality, failure to lay eggs was probably symptomatic of nonspecific toxic effects rather than effects directed at the reproduction pathway. Consistent with toxicity exhibited in adults, I was 0097-6156/87/0355-0273S06.00/0 © 1987 American Chemical Society

Baker et al.; Synthesis and Chemistry of Agrochemicals ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

SYNTHESIS AND CHEMISTRY OF AGROCHEMICALS

274


a l s o t o x i c t o house f l y l a r v a e r e a r e d on a d i e t c o n taining this material. A l t h o u g h t h e p a r e n t compound 2 ( F i g u r e 1 ) , N , 2 - d i * phenylhydrazinecarboxamide, (nomenclature p r i o r to 1972: 1 , 4 - d i p h e n y l s e m i c a r b a z i d e ) i s a known l a r v i c i d e (.5-9)» a n d r e l a t e d c o m p o u n d s ^ a n d A w e r e d e s c r i b e d ( 1 0 ) as h a v i n g s i m i l a r a c t i v i t y , l i t t l e i s known r e g a r d i n g the l a r v i c i d a l e f f e c t i v e n e s s of f l u o r i n e ana l o g s i n t h i s c l a s s o f compounds.

J., 2,

Figure

R=2-F ; R « 2 , 4 - F R=R =H 1

2

X

1. S t r u c t u r e s o f

1, i ,

R=H, R = 4 - C H R=4-C1, R - 4 - C H 1

2

5

1

2

5

Ν,2-diphenylhydrazinecarboxamides

B e c a u s e t h i s i n f o r m a t i o n i s l a c k i n g a n d b e c a u s e J. r e s e m b l e d some r e c e n t l y r e p o r t e d l a r v i c i d a l thiosemicarbazones (1Λ ,_12 ) , we d e c i d e d t o s t u d y 1 i n d e t a i l . Also, since 2 ( 1 3 ) a n d r e l a t e d c h l o r i n e d e r i v a t i v e s (_14.>ΑΑ) fungit o x i c , we e v a l u a t e d JL a n d a n a l o g s a g a i n s t s e l e c t e d p l a n t pathogenic fungi. a

Synthesis

r

e

o f Compounds

The fî, 2 - d i p h e n y l h y d r a z i n e c a r b o x a m i d e s w e r e r e a d i l y s y n t h e s i z e d i n moderate to e x c e l l e n t y i e l d s . B r i e f l y , the method i n v o l v e d a d d i t i o n o f a s u b s t i t u t e d p h e n y l i s o cyanate to a s o l u t i o n or s l u r r y c o n t a i n i n g the a p p r o p r i ately substituted phenylhydrazine. When r e a c t i o n was c o m p l e t e , t h e p r o d u c t was i s o l a t e d b y f i l t r a t i o n ( i f p r e c i p i t a t e d ) o r by e v a p o r a t i o n o f t h e s o l v e n t and r e c r y s t a l l i z a t i o n of the r e s i d u e . Diazenecarboxamides 40~£§= ( T a b l e I V ) w e r e s y n t h e s i z e d by o x i d i z i n g t h e c o r r e s p o n d i n g h y d r a z i n e c a r b o x * a m i d e s w i t h f e r r i c c h l o r i d e (16). Although o x i d i z i n g a g e n t s such as bromine, N-bromoacetamide and chromic a c i d provided products i n acceptable y i e l d s , f e r r i c chloride was t h e r e a g e n t o f c h o i c e . To i l l u s t r a t e t h e p r o c e d u r e , t h e s y n t h e s i s o f 42^, 2 - ( 2 - f l u o r o p h e n y l ) - N - [ 2 - ( t r i f luoro» methyl)phenyl]-diazenecarboxamide, follows. To a s o l u t i o n o f t h e p r e c u r s o r _16 ( 2 . 0 g ) i n m e t h a n o l ( 3 0 m l ) was r a p i d l y a d d e d a n a q u e o u s s o l u t i o n c o n t a i n i n g f e r r i c c h l o r i d e h e x a h y d r a t e ( 3 . 4 g) i n w a t e r (8 m l ) . W i t h i n seconds t h e c o l o r of t h e o x i d a n t d i s s i p a t e d and t h e product p r e c i p i t a t e d . A f t e r 0.5 h r a t r o o m t e m p e r a t u r e , t h e m i x t u r e was p o u r e d i n t o w a t e r ( 2 5 m l ) a n d t h e p r o d u c t 3


25.

DEMILOETAL.

Carboxamidt Moieties

275

c o l l e c t e d by f i l t r a t i o n . R e c r y s t a l l i z a t i o n from c y c l o hexane a f f o r d e d 1.6 g (79%) o f 42, mp 102-105 C. A l l new compounds gave s a t i s f a c t o r y (+ 0.4%) c o m b u s t i o n a n a l y s e s f o r c a r b o n , h y d r o g e n and n i t r o g e n . Compounds s u b m i t t e d f o r b i o a s s a y were >98% p u r e .


Larvlcidal

Effects

o f Compounds

Bioassays. House f l y l a r v i c i d e t e s t s r e q u i r e d a m o d i f i e d (jL7^) , s e m i - d e f i n e d (18^) s y n t h e t i c d i e t t o r e a r larvae. A b r i e f d e s c r i p t i o n o f t h e t e s t method follows. F i f t y f r e s h l y d e p o s i t e d eggs ( f r o m NAIDM s t r a i n o f f l i e s ) were p l a c e d on t o p o f a g e l m a t r i x c o m p r i s e d o f water (8 m l ) , s y n t h e t i c house f l y d i e t (1.5 g ) , v i t a m i n m i x t u r e (0.5 m l ) , and t e s t compound a t the r e q u i r e d c o n c e n t r a t i o n . R e s u l t i n g l a r v a e were a l l o w e d t o d e v e l o p i n t h e g e l ( h e l d a t 27 C f o r t h e d u r a t i o n o f t h e t e s t ) t o t h e p u p a l s t a g e and pupae t h a t s u r v i v e d t r e a t m e n t were c o u n t e d . From c o u n t s , p e r c e n t i n h i b i t i o n o f p u p a t i o n was c a l c u l a t e d . S c o r i n g system ( b a s e d on p e r c e n t i n h i b i t i o n o f p u p a t i o n ) : 0, n o r m a l p u p a t i o n a t 100 ppm; +, 90% i n h i b i t i o n a t 50-100 ppm; +++, >90% i n h i b i t i o n a t 10-50 ppm; ++++, >90% i n h i b i t i o n a t 5-10 ppm; +++++, >90% i n h i b i t i o n a t 1-5 ppm. A b r i e f d e s c r i p t i o n o f the y e l l o w f e v e r mosquito (Aedes a e g y p t i ( L . ) ) l a r v i c i d e t e s t f o l l o w s . An a c e t o n e s o l u t i o n (0.5 m l ) c o n t a i n i n g t h e a p p r o p r i a t e amount o f t e s t compound was added t o a m i x t u r e o f d i s t i l l e d w a t e r (49.5 m l ) , Tween 80 (25 mg), and a s i n g l e p e l l e t o f r a b b i t chow ( R a l s t o n - P u r i n a ) . Twenty l a t e - 4 t h I n s t a r s (5-6 days p o s t h a t c h ) were added t o t h i s medium and the medium was i n c u b a t e d a t 27 C. The t e s t was t e r m i n a t e d when a l l l a r v a e d i e d o r when a d u l t s emerged from s u r v i v i n g pupae. P r e v i o u s l y d e s c r i b e d methods were used t o a s s e s s l a r v i c i d a l a c t i v i t y i n t h e f a l l armyworm, S p o d o p t e r a f r u g l p e r d a ( J . E . S m i t h ) (1_9) and i n t h e I n d i a n meal moth, P l o d i a i n t e r p u n c t e l l a ( H u b n e r ) ( 2 0 ) . Structure-Activity Relationships. E f f e c t s c a u s e d by i n i t i a l structural modifications i n t h e l e a d compound a r e shown i n T a b l e I . Replacement o f t h e oxygen i n ^ with s u l f u r caused complete l o s s o f a c t i v i t y . Replacement o f t h e p h e n y l m o i e t y a t t h e 2 - p o s i t i o n w i t h b e n z y l , h y d r o g e n , o r a l k y l gave i n a c t i v e a n a l o g s S i m i l a r y , replacement of N-phenyl w i t h hydrogen, a l k y l , or c y c l o a l k y l gave i n a c t i v e a n a l o g s 10-12. Clearly, l a r v l c i d a l a c t i v i t y i s r e s t r i c t e d t o compounds w i t h N,2-diphenyl s u b s t i t u t i o n . A c t i v i t y a l s o appears enhanced by f l u o r i n e s u b s t i t u e n t s · To f u r t h e r d e f i n e s t r u c t u r e - a c t i v i t y r e l a t i o n s h i p s , two s e r i e s o f compounds (13-22 and 23-30) were s y n t h e s i z e d and e v a l u a t e d ( T a ~ b l e ~ I I ) . Because 1^ was h i g h l y f l u o r i n a t e d , compounds s e l e c t e d f o r t h i s p a r t o f


276


Table

I.

Activity

Η


I

2 4 5

R

X

2-F-C^H, ο 4 6*5 II 4-Cl-C H C

F _ C

1 8 9 1Q 11. 12

4

H

26 4 2-F-C H CH 6

4

H

CF CH NCCH CH 3

2

2

2

F

C

H

2

" H " 6 4^ B

II

Graded Larvlcidal Activity

II Χ

6

i n Musca

Η

H No .

of hydrazinecarboxamides

2

0 0 0 0 s 0 0 0 0 0 0 0

a

R

l

2,4-F -C H 2

C

6

3

H

6 5 4-(C H )-C H Il ° 2,4-F -C H II II II 2

5

6

J

2

H

6

?!

H n

c

H

" 3 7 £- 6 n c

H

A s s e s s e d f r o m p e r c e n t a g e o f pupae treatment (corrected f o r c o n t r o l s ) . methods f o r key t o a c t i v i t y scale.

3

4

+ + + + + + + + + + 0 0 0 0 0 0 0 0

surviving larval See b i o a s s a y


25.


Table

I I .

L a r v l c i d a l a c t i v i t y o f Ν,2-diphenylhydrazine= c a r b o x a m i d e s i n Musca

Graded Activity

No.

R

1 13 14 i i 16 17 18 19 20 21 22

2,4-F

277

Carboxamide Moieties

DEMILOETAL.

9

2,6-F; 2-F 2- CF 3- C F ^ 4- C F ^ 4-Cl Η 4-CH 4-CH^0 2

J

Assessed treatment. scale .

+ + + + + + + + + + +

+ + + + + + + + + +

a

+ + + + + + + + + + + + +

No.

1 23 24 25 26 27 28. 29 30

Graded Activity

R

2-F 2,4-F 3,5-(CF ) 2,3,4,5?6-F 2-CN,3-F 4-CH 0 Η 4-C1 4-N0

+ + + + + + +

2

2

3

2

5

0 0 0

+ + + + + + + + + + + + +

f r o m p e r c e n t a g e o f pupae s u r v i v i n g l a r v a l See b i o a s s a y methods f o r k e y t o a c t i v i t y



278


the s t u d y were a d m i t t e d l y b i a s e d toward those w i t h fluorine substituents. I n a n a l o g s 13-22, t h e 2 - f l u o r o = p h e n y l m o i e t y o f 1^ was k e p t i n t a c t , a n d s u b s t i t u e n t c h a n g e s w e r e made i n t h e N - p h e n y l m o i e t y . Conversely, i n a n a l o g s 23-3J), t h e 2 , 4 - d i f l u o r o p h e n y l m o i e t y i n I was k e p t i n t a c t a n d s u b s t i t u e n t c h a n g e s w e r e made i n the 2-phenyl moiety. D a t a f r o m a n a l o g s 13-22 s u p p o r t e d t h e c o n c l u s i o n t h a t a c t i v i t y was i n f l u e n c e d b y t h e t y p e ( c o m p a r e 18,19 a n d gZ) a n d l o c a t i o n ( c o m p a r e 16,17,18 a n d ^,1^3,1^4) o f t h e s u b s t i t u e n t . Since a l l analogs i n t h i s s e r i e s were a c t i v e , s t r u c t u r a l v a r i a t i o n s i n t h i s a r e a o f t h e m o l e c u l e d i dn o t appear t o have a s i g n i f i cant i n f l u e n c e on a c t i v i t y . A c t i v i t i e s o f a n a l o g s 27 - 30., h o w e v e r , i n d i c a t e d a lack of c o r r e l a t i o n with para s u b s t i t u t i o n ( l o w a c t i v i t y o f J O may b e d u e t o i t s p o o r s o l u b i l i t y ) . C l e a r l y , none o f t h e s u b s t i t u e n t m o d i f i c a t i o n s improved a c t i v i t y o v e r 1^. I n t e r e s t i n g l y , e v e n u n s u b s t i t u t e d 23 had a p p r e c i a b l e a c t i v i t y . To f u r t h e r i n c r e a s e a c t i v i t y , a n a l o g s ( M - 3 4 J w e r e prepared. This s e r i e s (Table I I I ) combined optimum s u b s t i t u t i o n ( 2 - t r i f l u o r o m e t h y l ) f o rt h e N-phenyl m o i e t y w i t h optimum s u b s t i t u t i o n ( 4 - c h l o r o , 4-methoxy, etc.) f o rthe 2-phenyl moiety. None o f t h e c o m p o u n d s r e f l e c t i n g t h i s approach exceeded a c t i v i t y o b t a i n e d f o r 16. A g a i n , d a t a from l^-JJ, s u p p o r t t h ec o n c l u s i o n s u g g e s t e d b y a n a l o g s 27-30 : a c t i v i t y c a n n o t be c o r r e l a t e d with the e l e c t r o n i c p r o p e r t i e s of the para s u b s t i t u e n t on t h e N-phenyl moiety. D u r i n g t h e i r s y n t h e s i s , some h y d r a z i n e c a r b o x a m i d e s appeared s e n s i t i v e t o a i r o x i d a t i o n . Because o f t h i s and b e c a u s e c e r t a i n r e l a t e d phenyldiazenecarboxamided e r i v e d f u n g i c i d e s a r e more t o x i c t h a n t h e i r c o r r e s p o n d i n g h y d r a z i n e s (21^), n i n e (40-48) d i a z e n e (= a z o ) a n a l o g s o f I were e v a l u a t e d as p o t e n t i a l l a r v i c i d e s . D a t a i n T a b l e I V show t h a t f i v e a z o a n a l o g s were l a r v l c i d a l and, except f o r were e q u a l i n e f f e c t i v e n e s s to t h e i r h y d r a z i n e c o u n t e r p a r t s . I n no c a s e i n v o l v i n g a z o / h y d r a z i n e p a i r s was a c t i v i t y e x c e e d e d b y t h e a z o analog. This p a r a l l e l a c t i v i t y i s suggestive of a s i n g l e mode o f a c t i o n f o r t h e s i m i l a r b u t d i s t i n c t l y d i f f e r e n t compounds. E v i d e n c e t o f u r t h e r s u p p o r t t h e s i n g l e mode o f a c t i o n c o n c e p t was o b t a i n e d i n c l o s e l y m o n i t o r e d p a r a l l e l t e s t s w i t h a c o g n a t e p a i r l j ^ a n d 42. Results from t h e s e t e s t s ( a t l e t h a l and s u b l e t h a l d o s e s ) showed 16 a n d £2 w e r e e s s e n t i a l l y I n d i s t i n g u i s h a b l e i n t h e i r e f f e c t s on l a r v a l , p u p a l , and a d u l t stages o f d e v e l o p ment. B e c a u s e a z o a n a l o g s were no more e f f e c t i v e t h a n t h e i r h y d r a z i n e c o u n t e r p a r t s and because a l k y l a t i o n o f 33 ( a t t h e 2 - p o s i t i o n ) w i t h m e t h y l p r o v i d e d a n a n a l o g (incapable of azo formation) equal t o i n effectiven e s s , s y n t h e s i s o f a z o a n a l o g s was d i s c o n t i n u e d . A n a l o g s 49-54 ( T a b l e V ) s h o w a d d i t i o n a l m o d i f i c a tions investigated. A l l compounds i n T a b l e V were -



4-ci

x

2-CF, 2-CF: 2-CF: 2-CF;

R

Activity

+ + + +

+ + + +

+ + + + + + + 35 36 37 is 19

No.

3

2

2-Cl 4-CH 0 H 4-Cl 4-N0

R

2-F 2-F 2-F 2-F 2-F

χ

Κ

surviving l a r v a l treatment f o r key to a c t i v i t y s c a l e .

υ

N_, 2 - d i p h e n y l h y d r a z i n e c a r b o x a m i d e s


of

A s s e s s e d from p e r c e n t a g e of pupae controls). See b i o a s s a y m e t h o d s

H

M

for

2,4-F 4-CH 0

M 32 12

2

R

I I I .

No.

Table


3

+ + + +

+ + + + + + +

(corrected

0

+ + + +


i n Musca

280


Table

IV.

Activity

of diazenecarboxamides

Larvlcidal

N

X

R


R

40 41

2-F

42

2-F

43 44

2-F

45 46 47

2-F 2-F 2-F

48

H

2-F

L.E.D. C a u s i n g >90% Inhibition of P u p a t i o n (ppm)

2-Cl

R^

2 . 4 -

F - C H 2.5- F ; - C H 2-(CF;)-C H 6

3

6

3

6

2

F

C

H

" " n A

2-F-C^H7 C

Activity

i

0 No.

i n Musca

6«5

10(10)J 4

10(10) 5-10(5)° (50)

n.a. 5 0

H

,

10-50(10-50)°

5

< 8>

b

,b,c

n.a. ( n . a . ) , c; ; b ,c n.a. (n.a.)

a

b Lowest e f f e c t i v e dose. Number i n p a r e n thesis represents a c t i v i t y of hydrazinecarboxamide precursor. n . a . = No a c t i v i t y a t 1 0 0 ppm.


25.

DEMILOETAL.

Table

V.

281

Carboxamide Moieties

Ineffective compounds

hydrazinecarboxamides

H

and

related

H

rTto Downloaded by UNIV LAVAL on May 9, 2016 | http://pubs.acs.org Publication Date: November 3, 1987 | doi: 10.1021/bk-1987-0355.ch025

No.

4£

50

R

R

.31 Jl t-BuO"^-

x

2,4-F

2

2,4-F

2

51 F

H

ί F

Η

0

53

4-Cl HO 0

54

I W I ^

4-Cl

\ χ ^ 0 Η

a

Inactive bioas say.

a t 100 ppm

i n Musca

larvicide



282

i n a c t i v e i n Musca a t the h i g h e s t c o n c e n t r a t i o n t e s t e d . A l t h o u g h l i t t l e c a n be s a i d h e r e a b o u t t h e e f f e c t s o f h e t e r o c y c l i c s u b s t i t u t i o n (only the p y r a z i n e analog Ag was t e s t e d ) , l a c k o f a c t i v i t y i n a n a l o g s .50-54 c l e a r l y emphasizes the importance of phenyl s u b s t i t u t i o n at the 2-position. E f f e c t s of Compounds i n O t h e r S p e c i e s . Three analogs (XA>2Â * â i ) e f f e c t i v e a g a i n s t M u s c a w e r e e v a l u a t e d i n the Aedes d e v e l o p m e n t a l b i o a s s a y . Hydrazinecarbox= amides and e l i c i t e d strong l a r v l c i d a l e f f e c t s at t h e h i g h e s t c o n c e n t r a t i o n ( 1 0 ppm) t e s t e d ; 2 4 - h r p o s t t r e a t m e n t m o r t a l i t i e s were 92% and 100%, r e s p e c t ively. A l t h o u g h m o r t a l i t y d e c r e a s e d a t 1 ppm ( 2 2 % f o r 16 a n d 4 7 % f o r 3 6 ) , a d u l t e m e r g e n c e was c o m p l e t e l y i n h i b i t e d by 3 6 . U n l i k e r e s u l t s i n M u s c a , 42 ( a z o a n a l o g o f 1 J ) was i n e f f e c t i v e a t 10 ppm i n A e d e s . I n a c t i v i t y o f 42 was s u r p r i s i n g i n l i g h t o f a c t i v i t y i n Aedes p r e v i o u s l y r e p o r t e d ( 1 2 ) f o r Ν,2-diphenyldiazenecarboxamide· I n P l o d i a , h y d r a z i n e c a r b o x a m i d e s 1, 1 J and l j | were t o x i c t o l a r v a e when a d m i n i s t e r e d i n a l a r v a l d i e t a t 1000 ppm. H o w e v e r , a t 100 ppm a l l a n a l o g s w e r e n o n t o x i c and l a r v a e s u r v i v i n g t r e a t m e n t p r o d u c e d normal adults. R e p r o d u c t i o n i n d i c e s ( o v i p o s i t i o n , egg h a t c h ) o b s e r v e d from m a t l n g s of s u r v i v i n g a d u l t s were a l s o normal. A z o a n a l o g s o f i , J j a n d }Jl w e r e e v a l u a t e d i n P l o d i a a n d e x c e p t 4 2 ( n o n t o x i c a t 100 p p m ) , elicited e f f e c t s i d e n t i c a l to t h e i r h y d r a z i n e c o u n t e r p a r t s . A z o - a z i n e p a i r s J. a n d 4 0 , 13 a n d 4JL, a n d Jj> a n d 42 were a l s o e v a l u a t e d i n the S p o d o p t e r a b i o a s s a y . With o n l y minor d e v i a t i o n s , a u n i f o r m p r o f i l e of e f f e c t s was o b s e r v e d when t h e s e a n a l o g s were a d d e d t o a l a r v a l diet. F o r e x a m p l e , a t 100 ppm 1J> c a u s e d a s u b s t a n t i a l ( 2 0 - 3 0 % ) d e c r e a s e i n s i z e and w e i g h t o f pupae ( l o w l a r v a l m o r t a l i t y ) and s e v e r e l y i n h i b i t e d egg p r o d u c t i o n of a d u l t s t h a t s u r v i v e d l a r v a l t r e a t m e n t . Invariably, e g g s d e p o s i t e d by f e m a l e s , w h o s e o v i p o s i t i o n was sev e r e l y a f f e c t e d , d i d not h a t c h . A t 10 ppm, J j | h a d no e f f e c t on l a r v a l g r o w t h a n d d e v e l o p m e n t , a n d no e f f e c t on r e p r o d u c t i o n . A l t h o u g h i t i s n o t k n o w n how r e p r o d u c t i o n i s i n h i b i t e d by 2j6 a n d r e l a t e d c o m p o u n d s , t h e c o r r e l a t i o n between p u p a l s i z e and egg p r o d u c t i o n s u g g e s t s t h a t p u p a l h e a l t h and v i g o r a r e m a j o r contri buting factors.


a n c

Fungicidal

Effects

of

Compounds

Fungi t o x i c i t y Tests. F u n g i t o x i c i t y was d e t e r m i n e d by measuring i n h i b i t i o n of l i n e a r growth of f u n g i i n m a l t - e x t r a c t a g a r m e d i u m o n 100 χ 15 mm p e t r i p l a t e s i n c u b a t e d a t 25 C. An a c e t o n e s o l u t i o n o f t h e t e s t c o m p o u n d was a d d e d t o t h e m o l t e n a g a r ( 5 0 C) a n d t h e h o t m e d i u m was t h e n p o u r e d o n t o t h e p l a t e s . Final c o n c e n t r a t i o n of a c e t o n e i n t h e c o n t r o l and f u n g i c i d e


25.

DEMILOETAL.

Carboxamidt Moieties

283


t r e a t m e n t s w a s 0.5%. A f t e r s o l i d i f i c a t i o n , t h e medium was i n o c u l a t e d w i t h a 6 mm h y p h a l d i s c c u t f r o m a n a g a r c u l t u r e of the fungus. To f a c i l i t a t e comparison between compounds, doses ( E D ^ ) c a u s i n g h a l f - m a x i m a l l i n e a r growth i n h i b i t i o n were d e t e r m i n e d . Structure-Activity Relationships. T o x i c i t y t e s t s were conducted w i t h 3 hydrazinecarboxamides and 5 d i a z e n e c a r b o x a m i d e s on 3 p l a n t p a t h o g e n i c f u n g i , P y r i c u l a r i a oryzae, B o t r y t i s c i n e r e a , and M o n i l i n i a fructlcola. D a t a i n T a b l e V I show t h a t , e x c e p t f o r 46, a l l compounds a r e f u n g i t o x i c . F i v e compounds elicited e x c e p t i o n a l a c t i v i t y (

Larvicidal and Fungicidal Activity of Compounds with

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