CA1058215A - Insecticidal phenylhydrazone and bis-phenylhydrazone sulfides - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Phenylhydrazone and bis-phenylhdrazone sulfides of the formula:

Description

105l~lS

BACKGROUND OF THE INVENTION
Field of the Invention The present invention is concerned with insecticidal compounds which have morphogenetic hormonal mimetic activity. Compounds having morpho-genetic hormonal mimetic activity exert a disrupting influence upon the normal development of insects. These compounds interfere with the normal metamorphosis of the pest insects and result in the formation of individual insects of the treated species which develop abnormally and are nonviable or sterile. This ultimately leads, indirectly at least, to the destruction of the insect population.
Description of the Prior Art Thioketal-substituted phenylhydrazones are disclosed by M.W.
Moon et al, "J. Agr. Food Chem.," 20, 888 ~1972). German patent No. 2,157,601 ~ . 77 88470b (1972~] also disclose thio-substituted phenylhydrazones.
Phenylhydrazone compounds are also disclosed in "J. Agr. Food Chem.,"-20, 1187 (1972); "J. Org. Chem.," 37, 383, 386, 2005 (1972); and Netherlands patent application No. 7,1139497.
DESCRIPTION OF THE INVENTION
-The insecticidal phenylhydrazone sulfides of the invention are represented by the formula:

Cl IR
Ar - NHN = C - IC2 (S)n ~I) wherein Rl is hydrogen or alkyl of 1 to 6 carbon atoms, R2 is hydrogen or alkyl of 1 to 6 carbon atoms, R is ArNHN = C(Cl)C(R )(R ) -, alkyl of 1 to 6 carbon atoms, haloalkyl of 1 to 6 carbon atoms and 1 to 5 fluoro, chloro or bromo groups or phenyl unsubstituted, or substituted with up to 3 (0 to 3) fluoro, chloro or bromo; Ar is phenyl unsubstituted or substituted with up to 5 (0 to 5), more preferably with up to 3 (0 to 3), fluoro, chloro or

- 2 - ~

. ,~,..,.,:~

~ ~35~

bro~o or with up to 2 (0 to 2)~ more preferably with up to 1 (0 77 to 1~ nitro; ana n is 1, 2 or 3O 78 Representative alkYl groups ~hich Rl, R2 an~ R3 may 79 represent include methyl, ethyl, n-propyl, isopropyl, n-hutyl, B0 sec-pentyl and isohexyl. Representative haloalkYl R3 groups 82 include trifluoramethyl, chloromethyl, trichloromethyl, 83 1,1,2,2-tetrachloroethyl, pentabromoethyl, pentachloroethyl, 4- 85 chlorobutyl, etc. Representative halophenyl R3 groups include 87 4-fluorophenyl, 4-chlorophenyl, 3-bromophenyl~ 2,4 dichloro- 90 phenyl, and 2,4,6-trichlorophenyl. Representative halophenyl 93 Ar groups include 2-fluorophenrl, 4-fluorophenyl, 4-chloro- 94 phenyl, 2j4-dichlorophenyl, 3,5-dichlorophenyl, 2,4- 96 dibromophenyl, 2,4,6-tribromophenyl and pentachlorophenyl. 97 ~he preferred Rl and ~Z groups are alkyl of 1 to 3 98 carbon atoms. The preferred R~ qroup is alkyl of 1 to 6 carbon 100 atoms, haloalkyl of 1 to 2 carbon atoms and 1 to 5 chloro or 101 bromo, phenyl of up to 3 chloro or bromo or 102 ArNHN=C(Cl~C(~ R2~-. The most preferred ~3 group is alkyl of 103 1 to 6 carbon atoms or ArN~N=C(Cl)C(~)(R2)-. The preferred Ar 105 groups are phenyl and phenyl substituted with 1 to 5 chloro or 106 bromo groups, especially trichlorophenyl. 107 Representative compounds of formula (I) ~herein n is 10B
1, 2 or 3 are tabulated in Table I (0 represents phenyl~. 109 .

~8Z3~

TABLE I
Ar R1 R2 R3 C~3 ~1 C113-C~5 C1~3 C ~3 2-F~ C2~15 C2115 ClC1~2

3-Cl~ i-C3~17 i-C311~ ClzC11

4-Br~ C113 n-C411s CCl3 2,4-F2~ C~l3 n-C5l~ll C2Cl5 3,4-Cl2~ C113 n-C6~13 C113 3,5-Br2~ C113 C~13 C113 2,4,6-F3~ C~13 C113 . CCl3 2,4,6-Cl3~ C~115 C113 C113 2,4,6-Br3~ CH3 CH3 CH3 H H ~NI1N=CClCH2-2,4-C12~ H H 2,4-Cl2~NHN=CClCH2-m-02N~ H H m-02N~NHN=CClCH2~
H CH3 ~NHN=CClCH(CH3)-3~5-Cl3~ ~ C2H5 ~NHN=CClCH(CzH5)-2,4,6-Cl3~ H n-C3H7 2,4,6-Cl3~NHN=CClCH(n-C3H7)-3,5-F2~ H sec-C4Hg 3,5-F2~NHN=CClCH(sec-C4Hg)-2,4,6-Br3~ H n-csHll 2,4~6-Br3~NHN=CClCH(n-C5H11)-2,4,6-Cl3~ E~ n-C6H13 2,4,6~Cl3~NHN=CClCH(n-C6Hl3)-3t5-cl2~ CH3 CH3 3,5-Cl2~NHN=CClC(CH3)2-2,4,6-Cl3~ CH3 CH3 2,4,6-Cl3~NHN=CClC(CH3)2-2,4-(02N)2~ CH3 CH3 2,4-(02N)2~NHN=CClC(CH3)2-2,6-Cl2-4-Br~ C2H5 C2H5 2~6-cl2-4-sr~NHN=cclc(c2H5) 2,4,6-Cl3~ n-C6H13 CH3 2,4,6-Cl ~NHN=CClC(CH3)2-~ class of preferred phenylhydrazone sulfides of 113 formula ~l~ are those wherein R1 and R2 individually are alkyl 114 of 1 to 3 carbon atoms, R~ i5 alkyl of 1 to fi carbon atoms, 115 chloroalkyl of l to 2 carbon atoms and l to S chloro, or phenyl 117 of up to 2 chloro or bromo, Ar is phenyl substituted with up to 118 S chloro, bromo or fluoro, more preferably phenyl substituted 119 with up to ~i chloro, and n is 1, 2 or 3. 120 A preferred class of bis-phenylhydrazone sulfides of 121 :Formula (I) are those wherein Rl is hydrogen; ~2 is alkyl of 1 122 to 6 carbon atoms, more preferably 1 to 3 carbon atoms; and Ar 123 is phenyl substituted with up to 3 fluoro, chloro or bromo, 124 more preferably phenyl substituted with up to 3 chloro or 125 bromo. 126 Another preferred class of bis-phenylhydrazone sul- 127 fides of formula (T) are those wherein R1 or R2 individually 128 1~)5~

are alkyl of 1 to 6 carbon atoms, preferably 1 to 3 carbon 129 atoms, and Ar is phenyl substituted with up to 3 fluoro, chloro 130 or bromo, more preferably phenyl substituted with up to 3 131 chloro or bromo. 132 The bis-phenylhydrazone compounds of the inYention 133 are prepared by reacting a bisalkanoyl acid chloride (II) with 134 a phenylhydrazine (~T~ and then reactina the resulting bis- 135 hydrazide (IV) with phosphorus pentachloride, as depicted in 136 reactions (1) and (2): 137 r ~
Lc1c_~5n + 2 ArNHNH2 ~ L~rNHNH~C~C~Sn ~ 2HCl (1) (II) . (IV) PC15~ , . 1 ( IV ) ~ ArNHN=C - C--Sn ( 2 ) 1' .

~herein P~, RZ, Ar and n have the same significance as pre- 139 viously defined. 140 Reaction (1~ is conducted by reactinq about 2 mols of 141 the phenylhydrazine (111) with about 1 mol of the bisalkanoyl 142 acid chloride in the presence of about 2 mols of an acid 143 acceptor in an inert solvent at a temperature of from about 01 144 to 50C, by more-or-less conventional procedures. Suitable 146 acid acceptors are trialkylamines, such as triethylamine, or yridine compounds, such as pyridine or alpha-picoline. 147 Reaction (2~ is conducted by reacting about 1 mol of 148 the bishydrazide ~IV) with about 2 mols of phosphorus penta- 149 chloride in the presence of an inert solvent at a temperature 150 of about 251 to 1001C, and then working up the product mixture 151 1~5~Z~S
with phenol. Suitable inert solvents are chlorinated hydrocarbons such as carbon tetrachloride and methylene dichloride. Reaction (2) is a known reaction for the chlorination of hydrazldes, as disclosed in Netherlands Patent Application No. 71.13497 and in United States Patent 3,745,215.
The phenylhydrazone sulfides of the invention wherein n is 2 or 3 may be prepared by reacting a bishydrazone (V) with excess chlorine and then reacting resulting sulfenyl chloride (VI) with a mercaptan as depicted in the following reactions (3) and (4).

IH Rl C12 Cl Rl [Ar - NHN = C - f - S~2 ~ Ar - NHN = C - C - (S)n_l (3) (V) R2 (VI ) R3SH Cl Rl (VI) - ~ Ar - NHN = C - Cl - (S)n - R (4) (VII) (I) R

10wherein n is 2 or 3, and Rl, R2, R3 and Ar have the same significance as previously defined, and R3 is alkyl, haloalkyl, phenyl or substituted phenyl.
Reaction (3) is conducted with about 2 to 11 mols, preferably 3 mols to 3.5 mols, of chlorine per mol of the bishydrazone (V) in an inert solvent, e.g., chlorinated hydrocarbons such as methylene chloride and Garbon tetrachloride, at a temperature of 0 to 50C. The resulting sulfenyl chloride (VI) may be isolated and purified. However, it is generally more convenient to react the sulfenyl chloride (VI), without purification, with a substantially equimolar amount of the mercaptan (VII) at a temperature of 0 to 50C to produce the product (I). The product (I) is isolated and purified by conventional procedures such as extraction, filtration, crystalliz3tion and chromatography.

~-é ~i . :~.., 2~L5 Ihe phenylhydrazone sulfides of the invention wherein n is 1 or 2 are prepared by reacting a hydrazide sulfide (VIII) with phosphorus pentachloride as depicted in reaction (5):

O Rl Cl Il 1 3 l l Ar - NHNH - C - C - S - R ~ PCI5 --~ Ar - NHN = C - C - Sn - R3 (5) (VIII) (I) wherein n is 1 or 2, and Rl, R2 and Ar have the same significance as previous-ly defined, and R3 is alkyl, haloalkyl, phenyl or substituted phenyl.
Reaction (5) is conducted by reacting substantially equimolar amounts of the hydrazide sulfide (VIII) and phosphorus pentachloride in the presence of an inert solvent at a temperature of about 0 to 100C, and then working up the product mixture with phenol. Reaction (5) is a known reaction for the chlorination of hydrazides, as disclosed in Netherlands Patent Application No. 71.13497 and in United States Patent 3,745,215.
I~he hydrazide sulfide reactant (VIII) is suitably prepared by reacting substantially equimolar amounts of an aryl hydrazine (III) and an alkanoyl halide (IX) in the presence of an acid acceptor in an inert solvent at 0C to 50C, as depicted in reaction (6):

O Rl O
Il l 3 11 1 Ar - NHNH2 ~ X - C - Cl Sn ArNHNH C - I - Sn - R3 (6) (III) (IX) (VIII) wherein n is 1 or 2, X is chloro or bromo, and Rl, R2, R3 and Ar have the same significance as previously defined.
The hydrazide monosulfide reactant (VIII) (n = 1) is also suitably prepared by alkylating a bromo-hydrazide of the formula .
. ~
. . .

~5~2~

O Rl ll l Ar-NllNll~C-C-Br (X) with an alkali metal mercaptide of the formula R~SM wherein N 215 is an alkali metal and R~, ~Z and ar have the same significance 217 as previously defined, and ~ is alkyl, haloalkyl, phenvl or 218 substituted phenyl. The bromo-hydrazide reactant ~X) is 219 suitably prepared by reacting the aryl hydrazine (III) and an 220 alpha-bromoalkanoyl halide. 221 ~he co~pounas of the invention are useful as morpho- 222 genetic hormonal mimetic insecticides, particularly, against 224 insects such as cabbage lcoper larvae, alfalfa weevil larvae, 225 yello~ mealworm, kissing bug and mosquitos. 226 The compounds are very potent and are used at 227 extremely low concentrations. For example, compositions 229 containing lO0 ppm to O.Ol ppm, preferably from 5 ppm to O.l 230 ppm, are effective for inhibitinq or interfering with the 231 normal metamorphasis of insects. However, the effective 233 concentration depends in part on the mode of applicatlon and 234 the particular insect.
The compounds may be applied in either liquid or 235 solid formulations to the pre-adult insects or their habitats. 236 For example, they may be sprayed or otherwise applied directly 237 to plants or aqueous bodies so as to effect control of insects 238 coming into contact therewith. 239 Formulations of the compounds of this invention will 240 comprise a metamorphosis-inhibitinq amount of one or more of 242 the compounds and a biologically inert carrier. Usually they 243 will also contain a wettin~ aqent. Solid carriers such as 244 cla~, talc, sawdust, alfalfa meal, and the like may be used in 245 such formulations. Liguid diluents which may be used with 246 ~51~2~i these compounds include water aliphatic and aromatic solvents. 247 In addition, these formulations may contain other compatible 248 pesticides, fillers, 5t~abilizers~ attractants and the like. 249 ~ he concentration of the active ingre~ient to be used 250 with inert carriers, either solid or liquid carriers, will be 251 dependent upon many factors, such as the particular compound 252 which is used, the c~rrier in or upon ~hich it is incorporated, 253 the method and conditions of application, the insec~ species to 254 be controlled, e c., the proper consideration of these factors 255 beinq within the skill of those versed in the art. In general, 257 the toxic inqreaients of this invention will be effective in 258 concentrations from about O.OOOl~ b~ weight to as high as 50%
by weiqht or higher. Economically, of course, it is desirable -260 to use lower concentrations of this active ingredient. 261 The compounds of the invention are particularly 262 useful in combination with mosqui~o larvicidal petroleum oil 263 dispersions. Petroleum oils suitable as mosquito larvicidal 264 dispersions are known. Such hyarocarbon oils include mineral 265 oils such as naphthenic base and paraffinic base lubricating 266 oils, etc., as well as synthetic oils. Such hydrocarbons oils 268 are nonphytotoxic ana generally contain not more than a few 269 percent aromatics. ~articularly suitable hydrocarbon oils have 270 boiling points above 350 to 400F. and viscosities of frcm 271 about 33 to 200 SSIl at 100~.
The amount of the compound of the invention employed 272 in petroleum oil qenerally ranges from 0.1% to 10% by weiqht 273 based on weight of oil. The hydrocarhon oil dispersions 275 containinq the compounds of the invention are contacted with or 276 applied to the surface of the agueous bodies wherein ~osquito 277 control is desired hy conventional methods.
The terms "insecticide" and "insect" as used herein 278 refer to their broad and commonly understood usage rather than 279 _ g _ ~0~
to those creatures which in the strict bioloqical sense are 280 classified as insects. Thus, the term "insect" is used not 281 only to include small invertebrate animals belonqing to the 282 clacs Tnsec a but also to other related classes of arthropoas 283 whose members are se~mented in~ertebrates havin~ more or fewer 2e4 than six leqs, such as spiders, mites, ticks, centipedes, ~orms 285 aDd the like.
~ x_mP~ 288 A mixture of 21.2 g. 2,4,6-trichlorophenylhydrazine, 291 10.3 g. 2i2'-dith;obisisobut~raldehyde and 100 ml. ethanol ~as 293 heated to re1ux and filtered hot. The solvent was evaporated 295 to leave a solid. The solid was washed with ~0 ml. hexane and 296 filtered to give l~.fi g~ of the bis-hydrazone product, m.p. 85- 297 110C. ~ecrystallization from hexane and then from ethanol 299 qave the proauct as a white solid, m.p. 116-117C. Elemental 301 analysis for C20H20Cl~N~S~ gave: ~S, calc. 10.8, found 10.8 302 ~Cl, calc. 35.9, founa 34.5. 303 To a cooled (0C) and stirred mixture of 8.0 g. of 306 the bis-2,4,6-trichlorophenylhydrazone of 2,2'-dithiobis~
isobutyraldehyde (prepared above) was added 3.3 g. chlorine in 308 50 ml. carbon tetrachloride over a 30-minute period~ The 309 mixture was filtered and the excess chlorine was removed under 310 reduced pressure. To the reaction mixture was added 2 g. 311 methvl mercaptan. The solYent vas then stripped to leave 9.7 312 q. of a red oil. Nuclear maqnetic resonance sprectroscopy 313 showed that the oil was a mixture of hydrazone sulfides of the 314 formula: Cl Cl--~ NHN=C - C - (S) -C113 Cll 3 Cl wherein n is 2 or 3. 318 ~)s~
The oil was chromatographed on silica qel (hexane 319 eluant) to give a product (3.1 q.~ consisting predominantly of 320 the hyarazone trisulfide (n equal to 3). Sulfur analysis for 322 the product was 19.0~ and chlorine analvsis for the product was 323 38.~.
~_ample_2 326 A solution of 3.3 q. chlorine in 50 ml. carbon 328 tetrachloride was aaded dropwise over a 30-minute period to a 329 cooled (0C) and stirred m ix~ure of 8.0 g. of the bis-2,4,6- 331 trichlorophenylhydrazone of 2,2'-dithiobisisobutyraldehyde in 333 100 ml~ carbon tetrachloride. ~he reaction mixture was 334 filtered to remove a little solid material and then partially 335 evaporated to remove excess chlorine. ~ 2.4 g. sample of 2- 336 methyl-2-propanethiol ~as added and the resultinq solution 337 stirrea for one hour at about 25C. The solvent was then 339 stripped to leave 10.4 g. of a red oil. The oil ~as 340 chromatographed on silica gel (hexane eluant~ to give 2.6 q. 341 the hyarazone trisulfide of the formula:
/ Cl ~ Cl CH3 CH3 Cl ~ N~N=C - C - SSS-C - C~13 Cl Elemental analysis for C~4Hl~Cl4N2S3 showed: %S~ calc. 21.8, 343 found 21.2; %Cl, calc. 30.9, found 31.4. The hydrazone 345 trisulfide was a red oil which solidified on standinq to a low- 346 melting red solid. 347 ~xam~le 3 350 ___ _ ___ _ A 24 g. sample of chlorine was bubbled into a mixture 352 of 14.5 g. of the bis-phenylhydrazone of 2,2~-dithiobis- 354 isobutyraldehyde over a one-hour period. After stirrinq at 358 about 25C. for three hours, 5 g. of ethanethiol were added and 359 ~:3S~2~S

the resultinq solution stirrea overnight. The solvent was then 360 stripped to leave a red oil. ~he oil was chromatographed on 361 silica gel ~benzene eluant) to give 15 g. of a rea oil. 362 Nuclear magnetic resonance spectroscopy and elemental analysis 363 (found 12.6~S, 37.2~Cl~ showed the product to be a mixture of 364 h~drazone sulfides of the formula: 365 Cl Cl--~HN=C - C - (S) -CH2CH3 Cl CH3 wherein n is 2 or 3. 368 The hydrazone disulfide (n = 2~ was the predominant 369 product. 370 ~x_m~ 4 373 A 23-g sample of 2-bromo-2-methylpropionyl bromide 375 was addea dropwise to a cooled (0C.~ slurry of 21.2 g 2,4,6- 378 trichlorophenylhydrazine and 7.9 g pyridine in 500 ml glyme 379 over a 2-hour period. The reaction mixture was stirred l/2 380 hour ana pourea into S00 mI ice water and 20 ml concentrated 381 hydroc~loric acid. ~ solid separated. The solia was filtered, 383 washed with uater and driea to give 27.3 ~ of the bromo- 384 hydrazid~ product (Formula X where ~r is 2,4,6-trichlorophenyl 386 ana ~l and R2 are methyl) as a beige solid, m.p. 10l-lO3C~ 387 ; Soaium mercaptide was prepared by bubbling methyl 388 mercaptan into a slurry of 5.~ q sodium hydride (54% in mineral 3B9 oil) in l50 ml dimethylformamide. The sodium mercaptide solu- 391 tion was then cooled in an ice water ba~h while 44.9 g o~ the 393 bromo-hydrazide preparea above in lO0 ml dimethylformamide was 394 added over a one-hour period. After stirring for 15 minutes, 395 150 ml benzene and 300 ml ice water were added. The benzene 397 layer was separated, washed with ~ater~ dried over maqnesium 398 sulfate and evaporated to qive a solid. ~he solid was 399 ~al5~z~i crystallized from lO0 ml boiling hexane to give 38.3 g of the 400 mercapto-hydrazide product (Formula VJI~ where Ar is 2,4,6- 401 trichlorophenyl, ~1, R2 and R~ are methyl and n is l~ as a 402 beige solid, m.p. 85-~9C. 403 ~ solution of 22 q of the mercapto-hydrazide prepared 404 above and 14 g phosphorus pentachloride in lO0 ml carbon tetra- 405 chloride was stirred at about 25C. for 2 days and then 406 re1uxed for 30 minutes. The reaction was then cooled (0C.) 408 and 18.9 g phenol was added in one portion. The reaction 410 ~ixture was then st;rred at 25C. for 5 days. 25 ml of 411 methanol ~as added to the reaction mixture and the resulting 412 solution was stripped to give an oil. The oil was chromato- 413 qraphed on silica gel (benzene/hexane eluant) to give lO.2 g of 415 an oranqe oil ~hich solidified on standing to an oranqe solid.
Recrystallization from hexane gave 6.4 q of the hydrazone 417 sulfide product, m.p. 5l-52C, of the formula 418 Cl Cl CH3 Cl - ~ - NHN=C ~ C - S-CH3 Elemental analvsis showed: %S, calc. 9.~, found 9.4; %Cl, 420 calc. 41.0, found 41Ø 421 ~__mPl__5 424 A solution of 16.4 ~ 2-methyldithio-2-methylpropionic 427 acid and 25 ml thionyl chloride was stirred and refluxed for l 429 hour. The reaction mixture was then distilled to give 10.5 g 430 of 2-methyldithio-2-methylpropionyl chloride, h.p. 100-122C at 432 55 mm of ~a. 433 The 10.5-q sample of propionyl chloride prepared 434 above was added dropwise over a lO-minute period to 12 g 2,4,6~ 435 trichlorophenylhyarazine and 6 q triethylamine in 250 ml glyme. 436 ~S~3Z~5 After stirring for l0 minutes, 200 ml ice water and l0 ml 437 concentrated hydrochloric acid were added. On stirrinq in an 439 ice bath, a solid separated. The solid was filtered, washed 440 with water, dried and recrystallized from hexane to give the 441 hydrazide product ~Formula VIII, where Ar is 2,4,6-trichloro- 442 phenyl, Rt, R~ and R~ are methyl and n is 2~ as a beiqe solid, 443 m.p. 86-a8~c~ 444 By a procedure similar to that of Example 4, the 445 hydrazide product prepared above was chlorinated with 446 phosphorus pentachloride to give the hydrazone disulfide 447 product of the Pormula /Cl Cl - ~ NHN=C - C - SS-CH3 Cl Elemental analysis for Cl~H~zCl~N252 sho~ed: %S, calc. 17~0, 449 found 17.1; %Cl~ calc. 37.5, found 40.9. 450 Rxam~les 6-13 453 By a procedure similar to that of Examples 1-5, other 455 phenylhydrazone compounds o~ Formula (I~ were prepared. ~hese 458 compounds are tabulated in Table II. 459 Example 14 -- Preparation of the bis- 462 Ph ylhyd--zone--f-2~2~-d-th--kls-so-u-yr~l chlo_lde 463 ~ ~ - NHN=C - C - ~

A solution of 14.4 q 2,2'-dithiobisisobutyric acid 467 (Chem. Abs. 64, 6fi35b) and 40 ml thionyl chloride was stirred 468 and refluxed ~or 1 hour. The excess thionyl chloride was 470 removed by evaporation under reduced pressure. The resulting 472 acid chloride product ~as diluted with 30 ml methylene chloride 473 ~ 14 -~)5~5 and added over a 20-minute period to a cooled solution of 13.1 g phenyl-hydrazine, 13.5 g triethylamine and 150 ml glyme. The reaction was then diluted with 300 ml water and extracted with methylene chloride. The methylene chloride extracts were dried over magnesium sulfate and evaporated to give a dark solid. The solid was recrystallized from hexane-benzene to give 11.3 g of 2,2'-dithiobisisobutyric acid bis~phenylhydrazide, as a beige solid, m.p. 144C. Elemental analysis for C20H26N402S2 showed: %S, calc-15.3; found 13.7.
A solution of 9.4 g 2,2'-dithiobisisobutyric acid bis-hydrazide, 10.0 g phosphorus pentachloride and 100 ml carbon tetrachloride was stirred and refluxed for 5 hours. The solution was then cooled and added over 20 minutes to a solution of 13.5 g phenol in 100 ml carbon tetrachloride.
Finally, 100 ml ethanol was added to the reaction mixture. The reaction mixture was then stripped to give 19 g of an oil. The oil was chromato-graphed on silica gel (benzene eluant) to give 6.0 g of the product, as a viscous red oil. Elemental analysis for C20H2Llcl2N4s2 gave: %S, found 13.3; %Cl, calc. 15.5, found 14.8.
The above chlorination reaction with phosphorus pentachloride is similar to that described in Netherlands Patent Application No. 71.13497 and in United States Patent 3,745,215.
Example 15 - Bis-2,4,6-trichlorophenylhydrazone of _ 2,2'-dithiobisisobutyryl chloride Cl L ~ Cl CH3 \ Cl This product was prepared by a procedure similar to that of Exar~lple 14. m e product is a white solid, m.p. 123-.. . .

,,, .~.: ,, ~5~LS

124C. Elemental analysis for C20H~BCl~N~S2 gave: ~S, calc. 512 9.7, found 10.1; %cl, calc. 42.8; founa 43.1. 514 Example 16 -- Bis-phenylhydrazone of 517 2 2~-dithi_bis-~ro~___Yl__hl_E_de 518 Cl CH3 I~N=C ~ CH - S
~ ~2 This product was prepared by a procedure similar to 522 that of Example 14. The product is a ~iscous red oil. 524 Elemental analysis for C~8H20Cl~N~S2 gave: %S, calc. 15.0, 525 found 13.6; ~Cl, çalc. 16.6, founa 15.5. 527 Example 17 -- ~is-p-nitrophenylhydrazone 530 of 2 2'-dithiobis~ro~ion~l chloriae 531 _-- --__________ __ ___ __________ (~2N~ lN=C - CH - 5)~

This product was prepared by a procedure similar to 535 that of Example 14. The product is a yellow solid (m.p. ca. 537 80C~ which forms selectively stable complexes with solvents 538 such as benzene and chloroform. 539 Exam~ae_18__-_I__e___C___rol 542 The compounds of Examples 1-16 ~ere tested as juve- 544 nile hormonal mimetic insecticides by the following procedures. 545 Ca__ q__~o_~er_~Tr i-ho~lus-a--iL 548

5 microliters of an acetone solution containing a certain 552 concentration micrograms of the test compound were applied 553 topically to the entire lenqth of the body of a late-fifth- 554 stage cabbage looper larva. Normally lO larvae were treated 555 per test. The treated larvae were then fed until they pupated. 556 The pupae were then incubated until the adult emerged. ~he 55 3Z~5 mortality of the pupae and adults ~as determined. The 559 compounds t~stea, the concentration (mcg/insect) and the total pupal and adult mortali~y are tabulated in Table III. 561 Alf_lfa_W_ev~ 3pera_~_st_c3_~yllen_alL 564 ~lfala ~eevil larvae were tested by the sa~e 567 proceaure employed for ca~bage looper. The compounas tested, 570 the concentration (mcq/insect~ and the total pupal ana adult 571 ; mortality are tabulated in Table IV.
Yellow_~e_lworm_~T_neb_io_m_litorL 574 ~bout two-day-old yellow mealworm pupae were tested 578 by the same proceaure employed for cabbage looper. The 580 compounds tested, the concentration (mcg~insect) and the total pupal and adult mortality are tabulatea in Table V. 581 Kls_inq Bu~-lRh-dnlus-p--llx-u-L 584 ~ ate-fifth-staqe kissing bug nymphs ~24 hours after a 588 blood meal~ ~ere tested by the same procedure employed for 590 cabbage looper. ~he compounds tested, the concentration 591 (mcq/insect) ana the total larval, pupal and adult mortality 593 are ~abulated in Table VI.

Example TABL~ II Sulfur Analysis No Ar Rl R2 R3 nCalc Found 62,4,6-Cl3~ 11 11 C113 l lO.l 9.3 7 " 11 11 -CCl3 213.4 ll.l 8 " 11 11 C113 218.3 16.8 9 " El il i-C3}17 217.0 16.6 ~ ~1 C113 C113 217.6 15.3 ll " 11 C113 C113 l9.7 9.4 12 ~ 11 C113 -ccl2ccl2~l 212.4 12.0 13 ~ C~13 C113 4-Cl~ 213.5 17.6 T~BLE III
Cabbage Looper Control Compound No.Concentration% Mortali-t~

2 0.4 90

6 0~4 90

7 100 60

8 1.3 90

9 1.2 go TA~LE IV
Alfalfa Weevll Control Compound No.Concentration% Mortalit~
1 0.3 100 2 0.14 90 3 0.14 90 4 . 0.38 90 0.1~ 90 6 0.3 90 8 1.5.............. 90 0.3 90 11 1.6 90 13 0.46 90 TA~LE V
Yellow Mealworm Control Compound No. Concentration% M

1.6 90 2.1 ~
6 3.7 90 7 10 o 8 4.6 90 11 2.1 90 32~

TABL~ VI
. _ Kissing Bug Control Compound No.Concentration~ Mortality 2 lO 60 3 lO lO0 4 3.2 90 3.6 90 7 lO lO
8 lO 0 9 10 o ll 6.5 90

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A compound of the formula:

wherein R1 is hydrogen or alkyl of 1 to 6 carbon atoms, R2 is hydrogen or alkyl of 1 to 6 carbon atoms, Ar is phenyl unsubstituted, or substituted with up to 5 fluoro, chloro or bromo groups or with up to 2 nitro, n is 1, 2 or 3, and R3 is Ar - NHN = C(C1)C(R1)(R2)-, alkyl of 1 to 6 carbon atoms or haloalkyl of 1 to 6 carbon atoms and 1 to 5 fluoro, chloro or bromo groups, or phenyl unsubstituted, or substituted with up to 3 fluoro, chloro or bromo groups.

2. The compound of claim 1 wherein R3 is alkyl of 1 to 6 carbon atoms or chloroalkyl of 1 to 2 carbon atoms and 1 to 5 chloro groups.

3. The compound of claim 2 wherein R3 is alkyl of 1 to 6 carbon atoms.

4. The compound of claim 3 wherein R1 is alkyl of 1 to 3 carbon atoms and R2 is alkyl of 1 to 3 carbon atoms.

5. The compound of claim 4 wherein Ar is phenyl unsubstituted, or substituted with up to 5 chloro or bromo groups.

6. The compound of claim 4 wherein Ar is phenyl unsubstituted, or substituted with up to 5 chloro groups.

7. The compound of claim 6 wherein Ar is 2,4,6-trichlorophenyl.

8. The compound of claim 7 wherein R1, R2 and R3 are methyl.

9. The compound of claim 7 wherein R1 and R2 are methyl and R3 is t-butyl.

10. The compound of claim 7 wherein R1 and R2 are methyl and R3 is ethyl.

11. The compound of claim 1 wherein R3 is ArNHN=CC1C(R1)(R2)-.

12. The compound of claim 11 wherein R1 is hydrogen, R2 is alkyl of 1 to 3 carbon atoms, Ar is phenyl unsubstituted, or substituted with up to 5 chloro or bromo groups.

13. The compound of claim 12 wherein Ar is phenyl unsubstituted, or substituted with up to 3 chloro groups and n is 2.

14. The compound of claim 13 wherein R2 is methyl and Ar is phenyl.

15. The compound of claim 13 wherein R2 is methyl and Ar is 2,4,6-trichlorophenyl.

16. The compound of claim 11 wherein R1 is alkyl of 1 to 3 carbon atoms, R2 is alkyl of 1 to 3 carbon atoms, and Ar is phenyl unsubstituted, or substituted with up to 5 chloro or bromo groups.

17. The compound of claim 16 wherein Ar is phenyl unsubstituted, or substituted with up to 3 chloro groups and n is 2.

18. The compound of claim 17 wherein R1 and R2 are methyl and Ar is phenyl.

19. The method for killing insects which comprises contacting pre-adult insects with a morphogenetically effective amount of a compound of

claim 1.