Terthienyl as Light-Activated Miticides - American Chemical Society

Chapter 28

Analogues of α-Terthienyl as Light-Activated Miticides 1

2

D. M. Roush, K. A. Lutomski, R. B.Phillips ,and S. E. Burkart

Downloaded by STANFORD UNIV GREEN LIBR on June 22, 2012 | http://pubs.acs.org Publication Date: December 7, 1991 | doi: 10.1021/bk-1991-0443.ch028

Agricultural Chemical Group, FMC Corporation, P.O. Box 8, Princeton, NJ 08543

This report summarizes some analogs o f α-terthienyl: 2aryl-5-dihalovinylthiophenes, 5-aryl-2,2'-bithiophenes and d i a r y l t h i a z o l e s . These compounds are l i g h t - a c t i v a t e d miticides. The synthesis, a c t i v i t y and s t r u c t u r e - a c t i v i t y relationship of each class of compounds w i l l be discussed. Over the past f i f t e e n to twenty years, there has been substantial interest i n the area of l i g h t - a c t i v a t e d pesticides. Table I shows a summary of the h i s t o r y of l i g h t - a c t i v a t e d i n s e c t i c i d e s . A more detailed h i s t o r i c a l perspective can be found elsewhere (1). Table I. History of Photo-Insecticides

Year

Compounds

Targets

Workers (reference)

1928 1950 1970 1971 1975

Xanthene Dyes

Mosquito Larvae

Methylene Blue Xanthene Dyes Xanthene Dyes

1981

a-Terthienyl

Codling Moth House F l y Fire Ant B o l l Weevil Face F l y House Fly Tobacco Hornworm Mosquito Larvae F r u i t F l y Larvae (Nematodes) Cabbage Looper Tobacco Budworm

A. H. D. L. J.

1988

Protoporphyrin

Barbieri (2) Schildmacher (3) Hayes (4) Butler (5) Heitz (6)

T. Arnason and G. Towers (7) J . Kagan (8) (F. Gommers) (9) C. Rebeiz (10)

1

Current address: Zoecon Research Institute, Sandoz Crop Protection, Palo Alto, CA 94304 Current address: Agricultural Research Division, American Cyanamid Company, P.O. Box 400, Princeton, NJ 08540

2

0097-6156/91/0443-0352$06.00/0 © 1991 American Chemical Society

In Synthesis and Chemistry of Agrochemicals II; Baker, D., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1991.

28. ROUSHETAL.

Light-Activated Miticides

353

The structures of the classes of compounds, along with at e r t h i e n y l (a-T), covered i n t h i s chapter are shown i n Figure 1. Since these compounds are s i m i l a r i n structure to a-T, i t i s presumed that the mechanism of action i s also s i m i l a r . The generally accepted mechanism of action f o r a-T i s a Type I I photosensitization of oxygen i n vivo. I t i s s i n g l e t oxygen that causes t o x i c i t y (1).


2-Arvl-5-dihalovinvlthiophene s Synthesis. The f i r s t set of compounds discussed are 2-aryl-5 d i c h l o r o v i n y l - (1, X-Cl) and 2-aryl-5-dibromovinylthiophenes (1, X-Br). Comparing this set of compounds with a-T, the central thiophene i s unchanged and the terminal thiophenes are replaced by substituted phenyl groups and the d i h a l o v i n y l moiety. Synthesis begins with the coupling procedure described by Kumada and co-workers (11). The catalyst used for most of the reactions was bis-(diphenylphosphino)propanenickel chloride (NidpppCl2), although other n i c k e l catalysts seem to be equally e f f e c t i v e . Unfortunately, following the actual experimental procedure resulted i n only 50-60% y i e l d s of the desired product when using a r y l Grignards other than phenylmagnesium bromide. A d d i t i o n a l l y , the other by-products make p u r i f i c a t i o n d i f f i c u l t . The reaction i s exemplified by the coupling of anisylmagnesium bromide and 2-bromothiophene, as shown i n Scheme I. Using chlorothiophene or iodothiophene does not increase the y i e l d of desired product. However, a procedural modification gives the desired products i n excellent y i e l d s with very l i t t l e by-products. In addition, t h i s improvement appears to be general when coupling with 2-bromothiophene. The modification, i l l u s t r a t e d i n Equation 1 by the reaction of tolylmagnesium bromide and 2-bromothiophene or 2-chlorothiophene, simply involves keeping the reaction at r e f l u x during the addition of the Grignard as well as the recommended reflux time after the addition i s complete. The arylthiophene derivatives can be formylated i n excellent y i e l d s by one o f two methods. Small scale reactions are more conveniently done by l i t h i a t i o n of the thiophene r i n g followed by reaction with dimethylformamide (Equation 2). Large scale reaction are more e a s i l y c a r r i e d out using standard VilsmeierHaack conditions. The dibromovinyl analogs, 4, are e a s i l y prepared i n high y i e l d s using published procedures (12). Using a s i m i l a r procedure for the synthesis of the d i c h l o r o v i n y l derivatives, 5, proves to be less successful (13). An alternate method i s procedurally cumbersome and the reported y i e l d s vary widely (30-80%) (14). As shown i n Equation 2, using bromotrichloromethane, instead of carbon tetrachloride as suggested by the l i t e r a t u r e (13), gives moderate to good y i e l d s of the desired products, 5. The use of zinc also gives a cleaner reaction. A c t i v i t y . A l l compounds reported i n t h i s chapter require l i g h t for a c t i v i t y . This l i g h t source used f o r these tests has the



Figure 1. Structures of a - t e r t h i e n y l and the compound classes reported i n t h i s chapter.

3




28. ROUSHETAK


355


SYNTHESIS AND CHEMISTRY OF AGROCHEMICALS II


28. ROUSHETAL.

357



wavelength centered at 356 nm and an i n t e n s i t y of 1600-2000 /iwatts/cm^. The plants (pinto bean, Phaseolus vulgaris) are infested with two-spotted spider mites (TSM or TSM-S, Tetranychus urticae) and sprayed to run-off with a 10% acetone-water s o l u t i o n of the test compound. The plants were placed under the l i g h t source and the data c o l l e c t e d at 24 and 48 hours. Tests were also done using phosphate (Azodrin) r e s i s t a n t mites (TSM-R). Structure a c t i v i t y relationships are based on the susceptible mite a c t i v i t y . Generally, the a c t i v i t i e s of the dibromovinyl- and dichlorovinylthiophenes (4 and 5 respectively) are s i m i l a r , as shown i n Table I I . For comparison, a-T has an LC50 value of 6 parts per m i l l i o n under i d e n t i c a l t e s t i n g conditions.

Table I I .

A c t i v i t y of 5-aryl-2-dihalovinylthiophenes (1) on Two-spotted Mites.

LC50 (ppm) TSM

1-10

X-Cl

3-Me; (CH)

X-Br

3-Me;

4

4-F; 4-OAc; 4-OS0 CH 2

3

10-30

H; 3-OMe; 4-OMe; 4-SMe;

H; 4-Me; 4-OMe; 4-SMe; (CH)

30-100

4-S0 CH3; 2-Me; 4-Me; 3-iPr

2-OMe; 3-OMe; 4-tBu

2

>100

4-OH; 40COC H ; 2-Me; 3-iPr 6

a-T LC50 (TSM)

5

- 6 ppm

The a c t i v i t y on phosphate r e s i s t a n t mites was suprising. I t had been assumed that there would be no cross resistance between the l i g h t - a c t i v a t e d compounds and other i n s e c t i c i d e s . However, as shown i n the Table I I I , there i s cross resistance with Azodrin. This cross resistance i s l i k e l y due to metabolism, and an increase i n oxidase a c t i v i t y would o f f e r a reasonable explanation. When methyl groups are added to the molecules or used to replace the halogen atoms, the resistance factor (LC50 of TSM-R + LC50 of TSMS) increases. I t i s also apparent from the data that this i s a rather s i m p l i s t i c explanation, and does not f u l l y r a t i o n a l i z e the cross-resistance. Based on the data generated from susceptible-TSM, a general s t r u c t u r e - a c t i v i t y relationship can be formulated. The rule-ofthumb i s to keep the rings and double bond as planar as possible. The s t r u c t u r e - a c t i v i t y rules are shown schematically i n Figure 2. Replacement of the v i n y l halogens with methyl groups does not decrease a c t i v i t y . The v i n y l hydrogen can be replaced with f l u o r i n e and the molecule retains the a c t i v i t y . Substitution a t the four-position of the thiophene does not adversely a f f e c t


4

358


Table I I I . A c t i v i t y of 5-aryl-2-dihalovinylthiophenes on r e s i s t a n t mites. LC50 (ppm)

TSM-R

TSM-S CI


0.5

Br 30 Br

C H: Br 6

15

Ο

5

6

50

1.1 (R=CH )

110

11 (R=Br) 4(R=CH )

24 75

3

Br

CH

0.9 (R=H)

3

Br 6

35

Br CH

CH

1.5

5

3

>100

Azodrin

Active=(CH ) Inactive=(C H )

(H, CH , C H )=Actlve

3

6

jj

Inactive=(ortho)

Active=(meta, para)—\" Ç)

3

6

5

5

|

^

CH (CH , CI, Br) =Active 3

2

Γ (H,F)=Active

Figure 2.

Structure-activity

of 5-aryl-2-dihalovinylthiophenes.


28. ROUSH ET AL.

359



a c t i v i t y . Only substitution with a large moiety (e.g. phenyl) i n the three-position of the thiophene r i n g , or s u b s t i t u t i o n at the ortho p o s i t i o n of the phenyl r i n g causes a loss of a c t i v i t y . Either of the l a t t e r two substitutions should cause the phenyl to become non-planar. However, the v i n y l group can s t i l l remain planar with substituents i n p o s i t i o n four of the thiophene. The a c t i v i t y of the dibromovinyl derivatives, 1 (X-Br), was used f o r QSAR analysis. The active compounds (defined as an LC50 value less than 15 ppm) have electron withdrawing substituents, R, and were i n a logP (calculated) range of 4.5 and 7.5. Linear regression gives the following equation:

log I/LC50 - 1.11 σ - 0.014 MR -0.83 (n - 12, r - 0.9)

(3)

where σ i s the Hammett substituent constant and MR i s the molar r e f r a c t i v i t y . The dependence of a c t i v i t y on an e l e c t r o n i c parameter, sigma, supports the premise of these compounds are behaving as photosensitizers. The need f o r l i p o p h i l i c compounds (vida supra) would support the hypothesis that these compounds act i n c e l l membranes i n a manner i d e n t i c a l to α-Τ (1). The c o r r e l a t i o n of a c t i v i t y and molar r e f r a c t i v i t y i s , at f i r s t , surprising. However, molar r e f r a c t i v i t y does have an electronic component which may account f o r this c o r r e l a t i o n (15).

5-Arvl-2.2'-bithiophenes Synthesis. This next set of compounds more c l o s e l y resemble a-T than the previously discussed class of compounds. These bithiophene derivatives, 2, can be synthesized by the two d i f f e r e n t routes shown i n Scheme I I . Each route has i t s advantages and disadvantages. The n i c k e l catalyzed couplings were discussed above. A l t e r n a t i v e l y , these compounds can be synthesized by r i n g closure of a 1,4-diketone. Preparation of tri-arylthiophenes by this l a t t e r route leads to a mixture of thiophene and furan. These reactions are published and w i l l not be discussed further i n this chapter (16,17). A c t i v i t y . These arylbithiophene analogs (2) of a-T are generally more active miticides than the previously discussed d i h a l o v i n y l derivatives, 1. As shown i n Table IV, most of the compounds have LC50 values below ten parts per m i l l i o n . The a c t i v i t i e s of a-T and the Uniroyal compound, UBI-T930, also a l i g h t - a c t i v a t e d miticide, (18) are included f o r purposes of comparison. A l l compounds i n Table IV were tested as described above.




360


28.

ROUSHETAL.

Table IV. Mites.

L C

A c t i v i t y of 5-aryl-2,2'-bithiophenes

(2) on Two-spotted

m

5 0 10

2

4-OC H ; 6

5

5

4-SMe

4-N0 ; 4-SOMe 2

aT LC Q (TSM)-6 ppm UBI-T930 LC (TSM)-1 ppm 5

50

The a c t i v i t y on phosphate resistant mites, shown i n Table V, also proved better than the dihalovinyl compounds discussed above. Interestingly UBI-T930 showed some cross resistance. As noted above, however, the simple explanation of an increase i n oxidase a c t i v i t y does not e a s i l y explain the observed cross resistance of UBI-T930. The general s t r u c t u r e - a c t i v i t y relationship f o r the bithiophenes, 2, appears i d e n t i c a l to that for the d i h a l o v i n y l derivatives, 1. For example, 3,4-diaryl-2,2'-bithiophenes would be inactive due to s t e r i c crowding of the a r y l and thiophene rings causing non-planarity of the pi-system. Also, a substituent i n the 4-position of the central thiophene r i n g of 2 causes a decrease i n activity.

QSAR regression analysis, done on a set of derivatives (II), gives the following equation: log 1/LC

50

- 0.41 (ClogP) - 0.39 MR - 0.43a(R)-0.0054(mp)-0.59 (n-27, r-0.75)

(4)

For this analysis, sigma values of para substituents were used for the thiophene substituents, R. ClogP i s the calculated logP value, MR i s molar r e f r a c t i v i t y and mp i s the melting point expressed as degrees Celsius. There are some s i m i l a r i t i e s of this regression equation and that from the dibromovinylthiophenes: high l i p o p h i l i c i t y i s desirable for a c t i v i t y and both equations have a negative c o e f f i c i e n t for molar r e f r a c t i v i t y . Melting point most l i k e l y represents a correction factor f o r the s o l u b i l i t y of s o l i d s i n a solvent. Compounds with a lower melting point would be more l i p i d soluble than the higher melting s o l i d s due to a lower heat of fusion (19,20).


S Y N T H E S I S A N D C H E M I S T R Y O F A G R O C H E M I C A L S II

362

A c t i v i t y of 5-aryl-2,2'-bithiophenes on r e s i s t a n t


Table V. mites.

LC TSM-S

Azodrin

2

S0

(ppm) TSM-R

>100


28. ROUSHETAL


363


Phenyl-Thienvl Substituted Azoles Using alpha-terthienyl as the model for t h i s t h i r d class of photoactivated miticides, an azole heterocycle was incorporated as the c e n t r a l anchor r i n g of molecule 3. Both oxazole and thiazole heterocycles were examined. A r y l and heteroaryl moieties were substituted about the azole. S t r u c t u r e - a c t i v i t y investigations are more complex for heterocycles such as oxazole and thiazole, which do not possess an axis of symmetry (Figure 3). No p a i r of alpha positions about either heteroatom i s i d e n t i c a l , i n contrast to the symmetrical thiophene. With the azole system, each s i t e of s u b s t i t u t i o n must be considered separately.

Synthesis. The preparation of these heterocycles was accomplished using t r a d i t i o n a l methodology. 2,4-Disubstituted and 2,4,5t r i s u b s t i t u t e d compounds were prepared v i a the Hantzsch (21) synthesis. The Gabriel (22) and Robinson-Gabriel (23) syntheses were used to prepare the 2,5-disubstituted thiazoles and oxazoles, respectively. The intermediate keto-amides could be converted into thiazoles by heating with P4S10 *- pyridine or with Lawesson's reagent (24). A series of 5'-thienyl derivatives were prepared using metalation chemistry. Thiazole 6 (Equation 4) was treated with 1.0 equivalent of η-butyllithium i n THF at -78°C for 2 h and the r e s u l t i n g anion quenched with 1.1 equivalents of an e l e c t r o p h i l e . Extractive workup and chromatography afforded the 5'-substituted derivatives i n 40-80% y i e l d . In the course of these experiments, we discovered that i t was necessary to avoid excess a l k y l l i t h i u m i n t h i s reaction sequence (Equation 5). Under these reaction conditions, excess base metalated both the thiophene and thiazole rings, r e s u l t i n g i n a mixture of mono- and b i s - a l k y l a t e d thienylthiazoles. n

A c t i v i t y . Our s t r u c t u r e - a c t i v i t y studies involved the evaluation of oxazoles and thiazoles as the c e n t r a l component, a r y l and heteroaryl substitution about the azole heterocycle and optimization of substituents on the peripheral aryl/heteroaryl moieties. A set of i d e n t i c a l l y substituted thiazoles and oxazoles were prepared to compare the effects oxygen vs. sulfur i n the parent azole heterocycle (Figure 4). In every case, the thiazole was 30 to 40 times more active than the corresponding oxazole. Our synthesis e f f o r t s , therefore, focused exclusively on the thiazole s e r i e s . Determination of the e f f e c t of the thiazole s u b s t i t u t i o n pattern on m i t i c i d a l a c t i v i t y was the f i r s t step i n structurea c t i v i t y optimization (Figure 5). Comparisons were made between s u b s t i t u t i o n about nitrogen (2,4) and s u b s t i t u t i o n about s u l f u r (2,5). Although a l l compounds i n these series were quite active, the 2,5-disubstituted compounds were 10 to 100 times more active than the 2,4-disubstituted compounds. The 2,4 system i s crossconjugated; there i s discontinuity i n the conjugation across the


364

S Y N T H E S I S A N D C H E M I S T R Y O F A G R O C H E M I C A L S II


Figure 3 .

Equivalence/non-equivalence of thiazole positions.

_X_

LC

Ο

5 0

(PPm)

_X_

30

S

Ο

0.7

Figure 4.

S

LC

5 0

(ppm)

50 16

A c t i v i t y of oxazoles versus thiazoles.

1) n BuLi/THF -78°C. 2 hr •F 2) Electrophile

Electrophile = CH I, (CH S) . (CH ) SiCI 3

3

2

3

3


(4)


28. ROUSHETAL.


365

three aromatic rings i n t h i s molecule. This e f f e c t i s r e f l e c t e d i n the UV absorbance. The 2,4,5-trisubstituted compounds were also very potent miticides (Figure 6). They were, however, l e s s potent than the 2,5-disubstituted compounds. F i n a l l y , we focused our attention on the 2,5-disubstituted thiazoles, s p e c i f i c a l l y phenyl and t h i e n y l substituted. Due to the non-equivalence of the 2- and 5-positions, we prepared several pairs of thiazoles to i d e n t i f y the most active s e r i e s . Not s u r p r i s i n g l y , both sets of compounds demonstrated excellent a c t i v i t y (Figure 7). In a l l cases, however, the 5-thienyl-2-phenyl thiazoles were more active. Substitution at the para p o s i t i o n of the phenyl moiety was shown to provide the most active compounds (para > ortho > meta). Our a c t i v i t y optimization studies and were therefore conducted on t h i s system (Figure 7). Pattern recognition using scatter plots indicated a strong c o r r e l a t i o n between m i t i c i d a l a c t i v i t y and sigma (r-0.88). Inactive compounds (-CN, -0S02Ph), most probably due to hydrolysis or metabolism, were not included i n the QSAR analysis. Linear regression gave the following equation: log

(1/LC ) - 0.64 σ - 0.016 η - 8, r - 0 . 8 8 50

(6)

Interestingly, sigma (and therefore a c t i v i t y ) was also c l o s e l y correlated with the calculated LUMO values (25) for these compounds (r - 0.82). The strong dependence of b i o l o g i c a l a c t i v i t y on e l e c t r o n i c parameters f i t s i n well with the assumption that these compounds e l i c i t t h e i r toxic e f f e c t s by photochemical generation of s i n g l e t oxygen. It was determined that s u b s t i t u t i o n of the 5'-position of thiophene resulted i n improved a c t i v i t y , most notably against organophosphate r e s i s t a n t two spotted spider mites (Table VI). This series of substituted t h i e n y l derivatives shows s u r p r i s i n g l y l i t t l e v a r i a t i o n when tested against a susceptible s t r a i n of TSM. It is assumed that the unsubstituted thienyl moiety i s susceptible to metabolic oxidation, and that simple s u b s t i t u t i o n (for example, methyl) a t the 5'-position s t a b i l i z e s the compound toward these oxidative processes. Substitution at the 5'-thienyl p o s i t i o n , therefore, enhances or maintains the b i o l o g i c a l a c t i v i t y of these compounds. This e f f e c t was further demonstrated when a series of methyl-thiophene derivatives were evaluated i n a "zero-day" residual assay (Table VII). In t h i s assay the plants were f i r s t sprayed with a solution of the t e s t compound, allowed to dry, infested with mites, then placed under the UV l i g h t s for 48 hours. The unsubstituted thienyl derivatives performed poorly i n this assay, whereas the methyl substituted analogs maintained a high l e v e l of m i t i c i d a l a c t i v i t y . From t h i s work, F5183, 5-(5-methylthienyl)-2-(4-trifluoromethyl phenyl)thiazole, emerged as a f i e l d candidate. This compound demonstrated excellent i n i t i a l and residual a c t i v i t y against both susceptible and r e s i s t a n t TSM i n the laboratory. Table VIII gives the comparative b i o l o g i c a l a c t i v i t y of F5183 to other photoactivated miticides.


366


Ο

CmS>

o - o

LC

LC

5 0 = 10 PPm λ max = 321 nm

λ

5 0

= 20 ppm

max =

3

3

4

PP

m


O-G-O LC λ

= 1.5 ppm

5 0

max =

Figure 5.

LC

5 0

3 3 8

n

LC

= 5 0

m

0

2

m

PP = 356 nm

2,4 versus 2,5-disubstituted thiazoles.

= 0.7 ppm

'Μδ) LC

5 0

= 2.5 ppm

Figure 6.

LC

= 5.4 ppm

2,5 versus 2,4,5-substituted thiazoles

0-0 R

LC50

5 0

(ppm)

-®R

LC50

(ppm)

CI

0.7

CI

1.8

F

0.7

F

1.4

Figure 7.

A c t i v i t y of 2,5-disubstituted thiazoles.


28. R O U S H E T A L



Table VI.

A c t i v i t y of 5'-thienylthiazoles.

% Control vs. TSM-s @ 20 ppm

R

Table VII. thiazoles.

367

H CH

3

F F

50 81

H CH

3

CF CF

53 96

3

3

A c t i v i t y of 5'-substituted versus 5'-unsubstituted

LC

5 Q

(ppm)

R

TSM-s

TSM-r

H

2.2

12

CI

1.7

CH

3

Si(CH ) 3

SCH

3

3

5

2.5

97% @ 5 ppm

2.1

29

4.8

7



Table VIII.

UBI-T930

2.5

13

100

0.9

0.5

1.4

11

39

6.2

0.9

>

TSM-r

TSM-s

Initial Activity (ppm)

7% @ 25

21% @ 5

21

OR

7 4 % @ 50

5 % @ 25

5 % @ 100

2 3 % @ 25

1R

8 % @ 50

0%@25

0%@100

3% @ 25

20

3R

R e s i d u a l Activity (ppm) vs. T S M - s

LC5Q or Percent Mortality

Residual a c t i v i t y of l i g h t - a c t i v a t e d miticides on two-spotted mites.


28. ROUSHETAL.

369


F5183 was evaluated i n a series of f i e l d t r i a l s against a v a r i e t y of mite species. F i e l d data for two of these t r i a l s i s provided i n Table IX. F5183 gave good control to 23 days against two spotted spider mite (TSM), Tetranvchus u r t i c a e . on cotton. This compound provided excellent control against c i t r u s rust mite, Phvllocoptruta oleivora. on c i t r u s (orange) (CRM). Excellent residual control was maintained for 33 days with good control continuing through 46 days.


Table IX.

F i e l d E f f i c a c y of F5183 %Control Days A f t e r Treatment

Rate ai/A)

13

23

on Cotton

0.2 0.075

60 87

90 70

CRM on Orange

0.025 0.05 0.1

99 99 98

95 99 99

Test

TSM

(lb

33

46

92 97 98

0 62 82

Conclusions We have described the s t r u c t u r e - a c t i v i t y relationships for three novel classes of photoactivated miticides. For each series studied, QSAR analysis has indicated that electronic parameters are important factors for b i o l o g i c a l a c t i v i t y . These studies led to the discovery of F5183 as a photoactivated miticide with excellent e f f i c a c y i n field trials. Acknowledgements The authors would l i k e to acknowledge to contributions of our many co-workers i n t h i s program. Judi A. Cannova, E. Mark Davis, Joanne DerPilbosian, Sue A. Herbert, Charles Langevine, and Albert J . Robichaud prepared most of the compounds discussed i n t h i s text. Kathleen A. Boyler, George L. Meindl and L i s a M. Schultz performed the many b i o l o g i c a l evaluations. Keith Rathbone conducted the f i e l d t r i a l s i n C a l i f o r n i a . Kenneth Goldsmith obtained the UV spectra for these compounds. Sandra M. K e l l a r and Charles J . Manly assisted i n the s t a t i s t i c a l analysis of the data sets. F i n a l l y , the authors acknowledge the support of the FMC Corporation. Literature Cited 1.

Light-Activated Pesticides; Heitz, J.R.; Downman, K.R., Eds.; ACS Symposium Series 339; American Chemical Society: Washington, DC, 1987.


370



2. 3. 4. 5.

Barbieri, A. Riv. Malariol, 1928, 7, 456. Schildmacher, H. Biol. Zentralbl., 1950, 63, 997. Hayes, D.K; Schechter, M.S. J . Econ. Entomol., 1970, 63, 997. Yoho, T.P., Butler, L; Weaver, J.E. J . Econ. Entomol. 1971, 64, 972. 6. Broome, J.R.; Callaham, M.F.; Lewis, L.A. ; Ladner, C.M.; Heitz, J.R.; Comp. Biochem. Physiol., 1975, 51C, , 117. 7. Arnason, T.; Swain, T.; Wat, C.K.; Graham, E.; Partington, S.; Towers, G.H.N.; Lam, J. Biochem. Syst. Ecol., 1981, 963; Wat, C.K.; Prasad, S.; Graham, E.; Partington, S.; Arnason, T.; Towers, G.H.N.; Lam, J . Biochem. Syst. Ecol, 1981, 9, 59. 8. Kagan, J.; Chan, G. Experientia, 1983, 39, 402. 9. α-Terthienyl was known to have nematicide activity which i s enhanced by UV light: Gommers, F.J. Nematologia, 1972, 18, 458. 10. Rebeiz, C.A.; Juvik, J.A.; Rebeiz, C.C. Pestic Biochem. Physiol., 1988, 30, 11. 11. Tamao, K.; Kodama, S.; Nakajima, I.; Kumada, M. Tetrahedron, 1982, 38, 3347. 12. Corey, E.J.; Fuch, P.L. Tetrahedron Lett., 1972, 3769; Ramirez, F.; Desai, N.B.; McKelvie, N.J. J . Am. Chem. Soc., 1962, 84, 1745. 13. Rabinowitz, R.; Marcus, R. J . Am. Chem. Soc., 1962, 84, 1312. 14. Speziale, A.J.; Ratts, K.W. J . Am. Chem. Soc., 1962, 54, 854; Speziale, A.J.; Tatts, K.W.; Bissing, D.E. In Organic Synthesis; Baumgarten, H.E., Ed.; John Wiley and Sons: New York, 1973; Collective Vol. 5, pp 361-364. 15. Hansch, L.A.; Unger, S.H.; Kim, K.H.; Nikaitni, D.; Lieu, E.J. J . Med. Chem., 1973, 16, 1207. 16. P h i l l i p s , R.B.; Herbert, S.A.; Robichaud, A.J. Synth. Commun., 1986, 26, 411. 17. Wynberg, H.; Metselaar, J. Synth. Commun., 1984, 16, 14, 1. 18. Relyea, D.I.; Moore, R.C.; Hubbard, W.L.; King, P.A. Proc. 10th Int. Congr. Plant Prot.; The British Crop Protection Council: Croydon, England, 1983; pp 355-359. 19. Bowman, B.T.; Sans, W.W. J . Environ. S c i . Health, 1983, B18, 667. 20. Yalkowsky, S.H.; Rinal, R.; Banerjee, S. J . Pharm. S c i . 1988, 77, 74. 21. Hantzsch, Α.; Weber, H.J. Chem. Ber., 1887, 20, 3118. 22. Gabriel, S. Chem. Ber., 1910, 43, 134, 1283. 23. Robinson, R. J . Chem. Soc., 1909, 95, 2167. 24. Pederson, B.S.; Lawesson, S.-O. Tetrahedron, 1979, 35, 2433. 25. Calculations performed using MNDO. Received December 22, 1989


Terthienyl as Light-Activated Miticides - American Chemical Society

Recommend Documents