CA1075248A - S-methyl 3-furfurylidene-2-methyl-dithiocarbazate and its use as a fungicide - Google Patents

Abstract

Abstract: The compound S-methyl 3-furfurylidene-2-methyl-dithiocarbazate and its use as a fungicide.

Description

iO75248 This inventi.on relates to a compound having fungicidal activity, and to processes for controlling or eradicating fungi using this compound.
Accordingly we provide the compound S-methyl 3-S furfurylidene-2-met~lyl-dithiocarbazate.
The compound may be made by any of the following methods:
Me SO

2 3 2 ` H2N-N-CSSK 2 4~ H2N-N-CSSCH3 -CH3 CHq ~/-- ~LCH=N-N-CSSCH3 ~ CHO

. Il B- 1~2N-N~-CH3+CS2+KOH ~ H2N-N-CSSK

--CII=N-N-CSSK ~ 4 ) ~--CH=N-N-CSSCH3 . ~ Ir~ ~1 Cs2-l-KOH
C. ~ ~ CHO~H2N-NH ~ ~ ~ CH--N-NH

~1-CH=N-N-CSSR 2S4~ ~LCEI--N-N
. CH3 CSSCH3 '' .
.' , , D. ~ ~ + (Ctl3)254 ~ ~ CH3 E. ~ CH3 ~ ~ ~ CH=N-NNa 2 CH=N-N-CS.SNa i ~ CH=N-N-CSSCH3

3 H=N-N-cSScH3 G. O ~Na+CSC12 ~ ~ CH=N-N-CS-Cl ~ CH=N-N-CSSCH3 . . .
H. ~ CH=N-NH + C53(CH~ ~ CH3 ~n a further embodiment of our invention we provide a process of era(licating undesired fungi which process comprisinE t~cating media infested with fungi with com-positions containing S-methyl 3-furfurylidene-2-methyl-dithiocarbazate.
It is to be understood that the fungicidally active compositions of this invention may comprise, in addition to the active ingredient described hereinabove~ one or more other compounds having fungicidal activity.
The compound and compositions of the invention ; may be used as foliar sprays for the control of fungi on plants but we have found that they are particularly useful ' as seed dressings.
Accordingly in yet a further embodiment of our invention we provide a process of treating seeds~ which process comprises treating seeds prior to sowing with a composition containing fungicidally effecti~e amount of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate.
: ! - In particular the present invention relates to a process of treating seeds to control or eradicate the incidence of fungi of the families Tilletia and Ustila~o thereon or therein.
l The fungi Til~etia and Ustila~o are diseases which may `,1 cause heavy damage to grain crops such as wheat and barley.
~ 25 It is known in the art that these diseases may be controlled . .

' by thc applic.l~ion of seed dressing compositions comprising an efective amount of a suitable fungicidal organo-mercury compound. ~lowcver toxicity and environmental studies have sho~n that tl~e use bf thcse compol~nds i.s highly undesirable~
and in addition some species of the fungi Tilletia exhibit resistance to them.
We have now found a compound which is highly effective against bunt and smut and which do not suffer the disadvantages of the prior art active ingredient compounds, and which in addition are highly effective against the resistant species of the fungi ?illetia.
The seed dressings of this invention may comprise, in addition to the S-methyl~3-furfurylidene-2-methyl-dithiocarbazate, one or more other compounds having fungicidal activity especially compounds active against cereal pathogens other than bunt. Such other compounds indicate for example fungicides such as, e.g., Mancozeb~ Thiram~ 8-hydroxy quinoline and insecticides such as, e.g., Lindane, Malathion.
I Especially useful compositions for use as seed dressing i 20 compositions comprise from 1 to 90% w/w preferably from 2.5%w/w to 75% w/w of the S-methyl 3-furfurylidene-2-methyl dithiocarbazate.
Our compositions may be formulated in the form of dusting powders or granules wherein the active ingredient is mixed with a solid inert carrier. Suitable solid inert carricrs may be, for example, kaolin, powdered chalk, talcs, kieselg~hr, dolomite, calci~ carbonate, powdered magnesia, Fullerls earth, gypsum~ ~le~ittls earth~ diatomaceous earth~
china clay, bentonite, and other colloidal clays.
Alternatively the seed dressing composit~ons may be in the form of dispersible powder orgranulescomprising~ in addition to the active ingredient an inert carrier comprising a wetting agent to facilitate the dispersion of the powder or ~anulesin liquids. Such powders or granules may include fillers, suspending agents and the like. The preferred dispersible powders comprise the active ingredient mixed with a finely ground colloidal clay together with a dispersing agent.
Suitable dispersing agents are known from the prior art and may be of the cationic~ anionic or non-ionic type. Suit-able agents of the cationic type include for example quaternary ammonium compounds such as cetyltrimethylammonium bromide.
Suitable agents of the anionic type include for example soaps~
salts of aliphatic monoesters of sulphuric acid, for example sodium lauryl sulphate~ salts of sulphonated aromatic compounds~
for example sodium dodecyl-benzene sulphonate~ sodiwm, calcium, or ammonium lignosulphonate~ butylnaphthalene sulphonate and a mixture of the sodium salts of di~isopropyl and tri-isopropylnaphthalene sulphonic acids. Suitable agents of the non-anionic type include for example the condensation products of an alkykene oxide such as ethylene oxide or propylene oxide . .

' J, ' ~

``l ' ,.''li , ~,. .
.'' ~ , .

~075248 Wit}l fatty alcohols such as oleyl alcohol or cetyl alcohol~
or with alkylphcll~ls such as octyl-phenol~ nonyl-phenol and octyl-cresol. Otller non-ionic agents are the partial esters derived from ,ong chain fatty acids and hexitol anhydrides~
the condensation products of the said partial esters with an alkylene oxide such as ethylene oxide or propylene oxide and the lecithins.
Suitable suspending agents are for example, hydrophilic colloids, for example polyvinyl pyrrolidone and sodium carboxy-methyl cellulose~ and the vegetable gums~ for example gumacacia and gum tragacanth.
We have found that deposition of a seed dressing composition containing S-methyl 3-furfurylidene-2-methyl-dithiocarbazate in an amount of from 50 to 1500 ppm effectively controls or prevent fungal growth to some extent at least.
For economic control of Tilletia ~. we prefer that seeds are treated so that they contain on their surface from 250 to 1500 ppm of the S-methyl 3-furfurylidene-2-methyl dithiocarbazate based on the weight of the seed.

.

,, ~ 1 .
~!
. ::
. . "

.

~075Z48 Our invcntion is illustrated by, but no way limited to, the following examples.
Example 1 This example describes the preparation of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate according to the equation i.e.

~'CHO + H2N - N - C - S - CH3 CH = N - N - C - S - CH3 Acetic acid (5 mls) was added to 50 ml of ethanol, this solution was warmed, and 2.7 g of S-methyl-2-methyl-dithiocarbazate .
was added with stirring. Furfuraldehyde (1.9 g) was added and a crystalline precipitate was obtained which was re-crystallized from ethanol yielding 3.3 g of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate melting at 98C. The identity of the product was confirmed by mass spectrometry. On further recrystallization from ethanol and charcoal the melting point increased to 104 C.
Example 2 This example describes the fungicidal action of compositions according to the present invention in vitro.
To a 1 ml volume of toluene was added 0.004 g of S-methyl '~' .

. ' ~' .
. . .

'' , ~ .

_ 9 _ 3-furfuryliden~-2-methyl-dithiocarbazate and 0.02 g of a 1:1 mixture by weight of ~IAlkanate~l CS (~Alkanate~ CS is a Registered Tradc Mark of ICI Australia Ltd for a proprietary anionic surface activc composition) and "Teric" 200 ("Teric"
is a Registercd Trade Mark of ICI Australia Ltd for nonionic surface active compositions comprising alkylphenol/alkylene oxide condensates).
This solution was thcn further diluted with water and mixed with molten agarto give weight per volume concentrations of active ingredient compound of 0.4, 2 and 10 ppm in the final product.
- The prepared agar mixtures were poured into petri dishes, allowed to solidify, and were then inoculated with ; spores of Tilletia foetida. A petri dish containing an agar composition comprising no active ingredient was prepared in a ' similar manner.
I In addition petri dishes containing agar compositions 1 comprising as active ingredient "Vitavax" (IlVitavaxll is a ; Registered Trade Mark of Uniroyal Inc for fungicidal compositions comprising as active ingredient 5, 6-dihydro-2-methyl-l~ 4-oxathiin-3-carbox-anilide) were prepared and inoculated substantially in the manner described above. After incubation of the inoculated slides at 10 to 18C for 7 days ... ....

:~ .

' ' ., "', ' , .

. - - :
: . , .

,,_ of spores was observed. The control obtained is shown in Table l below.
TABLE l Active Ingredient % Inllibition of Spores Compound (Rating*)-Concentration of Active Ingredient (ppm).

0 2 -- 0.4 , - _ ¦ ~ ~ C1 '~ C113¦ 3 ¦ 3 ¦ 2 '1Vitavax" 3 l 0 Control - No ~ctive 1ngredien~ 0 U 0 * Rating 3 = 90 - 100% Inhibition of spores 2 = 60 - 90% Inhibition of spores l = 30 - 60% Inhibition of spores 0 - 0 - 30% Inhibition of spores Example~3 This example describes the fungicidal action of a composition according to the present invention against the fungi - Tilletia foetida (B.H.C. susceptible) and ; Tilletia foetida (B.H.C. resistant) under field conditions.
Samples of wheat seed (c.v. Olympic)were inoculated '`.`' .
. . .

~q ~;~

''`` ;' ' ~ ' - ~.
.''., ' ' . .
. - , .

~ith spores of each of the fungal species Tilletia foetida (B.H.C susceptible) and Tilletia foetida (B H.C resistantl in the following manner. Spores of each fungus were admixed with wheat seed at a rate of 0 4 g of spores per 99 6 g. of seed and the mixtures were blended by rotation in sealed containers on the rollers of a ball mill for twenty minutes.
The samples of inoculated seed were then dressed with a fungicidal composition according to the present invention and comprising 50% w/w of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate, 3% w/w of ethylene glycol, 5% w/w of "Celite" 298, and 42% w/w of china clay, by application of the said fungioidal composition at a rate of 1 g per kg of inoculated seed and blending by rotation in a sealed con-tainer on the rollers of a ball mill for twenty minutes to produce uniform products containing 500 ppm by weight of active ingredient compound. "Celite" is a trade mark for a diatomaceous silica product, Each sample of dressed seed was then sown through a . ~
seed drill in 4 single row plots each 22 yards in length. The seed was then allowed to germinate and the wheat plants were allowed to mature. At harvest the seed heads were collected and the control of disease assessed. The percentage of diseased heads is presented in Table 11 below For purposes of comparison the sowing procedure described above was substantially repeated except that the dressed seed was replaced by samples of seed inoculated with each of the fungi .

', ~

-` 1075248 describcd above but not treated with a f-mgicidal composition.
Thc pcrc~ntage of diseased heads obtained in these comparative tests is also presented in Table 11 below.

;' ' ~ ., :' :'' 1 ' ` ' .

~' .1 ' ' .. .

:
:., , ~ ' ~t ' ' .

' '~
,'., ;
.: ' ' ' ' , , . ` .

~, P. ~ oo h~ :C C~ O .

H
. ~ .. . .
,., ~_ ~1 1 a ~
" v~

. . ~ U~
. . ~ o~
b~ c~
c ~ a ., . .~ 11 ~. , ¢ :~ o-,~
`,i _ ~

~"'' , . i .
.. .. .
.

10752`48 Examp]e 4 This cx.lmple dcscribcs the fungicidal activity of compositions of the present invcntion against Puccinia coronata (oat rust).
Two hundred millilitres of all aqueous composition comprising 0.05% w/v of S-methyl 3-furfurylidene-2-methyl dithiocarbazate was sprayed onto a pot of 30 5" tall oat plants. Twenty four hours after spraying the plants were inoculated with Puccinia coronata (oat rust) by dusting them with a concentrated spore suspension taken from infected plant material. After inoculation the oats were placed in a high humidity cabinet for 24 hours and then returned to the glass house. The plants were assessed eight days after inoculation and found to be substantially free of disease.
Examples 5 and 6 This example describes the control of the fungi Rhizoctonia solani (early blight of tomatoes), C~ratocYstis poradoxa (pineapple disease of sugar cane) and Venturia ine~ualis (black spot or apple scab).
~l 20 Small quantities of an aqueous ball milled suspension of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate were ; mixed with 20 millilitre volumes of an aqueous composition comprising 0.5~ w/w of potato dextrose agar and 0.5% w/w of water agar and the mixtures were then poured into petri dishes ~ 25 and allowed to set. Sufficient of the a~ueous suspension was :';' ~ .
.,.. ~

. . ~ J

; .

.

included to proYit3e agar c~inpositions having active ingredicnt concentrations of 10 ppm by weight and 25 ppm by weight in the final agar compositions.
A one centimetre cu~e of agar infected with Rhizoctonia S _lani~ Ceratocystis ~ or Venturia inequalis was then placed in each petri dish and the growtll of the fungi was assessed four days later. The results are presented in Table III below.
TABLE III
.... _ . _ , % Inhibition of Spores (rating)*

Fungal Species Concentration of Active Ingredient ~. ' . - ....
Rhizoctonia solani~ 3 3 Ceratoc~stis oradoxa 3 3 Venturia _neaual,is _ 3 . ............... , ............ ...

:;, * As for Example 2 , , ., ~

107~

Example 7 Analogues of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate as shown in Table IV below were prepared by reaction of a carbonyl compound (A) wlth various dithio-carbazates (B) according to the method of Example 1.

TABLE IV
..
Structure A B m.p.

ll I Me Me ll 1I Me S
0~ c ~ ~ O ~ O ~ H2N-N-C-S-Me ~ 89 ; ~LCH=N-Y ~ LHo ~ H2N-N-C S-B1 ~ 93 CH=N NH O --CHO N2N-NH-C-S-Me ~ 150 _~ ~ ~--CHO ~ H2N-NH-C-S-EC

,; ~ , .~
.

. f . .

Examplc ~
This exlmplc de.scribes the fun~icidal action of the analo~lles pr~parcd ill Example 7 in tlle field nnder natural conditions.
Wheat secd (c.v. Olympic)~ was inoculated with a mixture of equal amounts of Tilletia foeti~a spores HCB
rcsistant and IICB susceptible and Tilletia caries by admixin~ 1 g o~ the mixed spores with each lb of seed and then tumble mixing the mixture for 20 minutes. Separate samples of inoculated seed was then dressed with a composition by comprlsing 50% w/w of china clay and 50% w/w of each of the compounds listcd in Table V at rates of 0.01 g per 20 g of inoculated seed, 0.01 g per 13.3 g of inoculated seed and 0.01 g per 10 g of inoculated seed, and tumble mixing the mix~tures w~til uniform products containing 250 ppm, 375 ppm and 500 ppm com-pound respective]y were obtained.
For each Pungicidal composition and at each application rate~ dressed seed was then sown through a seed drill in 6 single row plots each 10 feet in length. The seed was then allowed to germinate and the wheat plants allowed to mature.
, The trials of each treatment rate were carried out in a different part of Victoria.
For purposes of comparison the sowing procedurc cles-cribed above was substantially repeated except that the dressed seed was replaced by untreated ino~lated seed.

: ;
.I .

- 18 _ At harvest the seed heads were collected and the control of thc disease assessed. The percenta~e of diseased heads is SllO~l in Table V below.
TABLE V

_ _ .
. ~ disease Compound 500 375 250 , ppm ppm ppm _ CH = N - - C - S - Me ~ 0.18 ~ 0.70 ~ 2.27 h 11 Me Me S
J -C - N - N - C - S - Me 25.79 4.73 25.79 C S _ Et 4-67 6.2 CH = N - NH - C - S - Me ~ 15.7710.70 ~ 11.21 ~

¦ I ~_CH = N - H - C - S - Et 15.30 17.10 14.93 ¦

Control (no treatment) 32.06 60.03 24.20 S The results obtained demonstrate tha~ the oompounds of .~,~,......... ' .
.:' .
'' .

Exalllple 7 l~a~-e activity against Tilletia foetida and Ti]]ctia ~ari(~s. Ilowevcr this activity is much less than the activity of the colllp()und of tlle present invention.
Examl)]c 9 11.8 g of potassillm hydroxide werc dissolvcd in 80 ml of ethanol. After the reaction mixture was cooled to 10, 9.2 g of methylhydrazine was added and the ~ixture stirred for 5 minutes.
14.5 g of carbon disulphide were added dropwise keeping the temperature between 10-15. The reaction mixture was stirred at room temperature for 2 hours. 120 ml of water was added~ then 27.8 g of dimcthyl sulphate was added dropwise keeping the temperature below 20. After stirring for 2 hours at room temperature, 18 g of furfuraldehyde was added dropwise and with vigorous stirring~ then the reaction mixture was stirred for 1/2 hour at room temperature. 200 ml of water was added, then the mixture was cooled below 10, then the precipitate was filtered off, washed with water, and dried at 60 in vacuum. Yield of S-methyl-3-furfurylidene-2-methyl-dithiocarbazate -- 36.5 g mp = 100 (90%).
s, . ~

5.9 g of potassium hydroxide were dissolved in 40 ml of ethanol and the solution cooled to room temperature, then 4.6 g of methylhydrazine was added. After cooling to 10~ 7.25 g of carbon disulphide was added dropwise with stirring~ keeping .
. ~ .

.

- 2~ -the temperaturc below 15. After stirring or 2 hours at room tcmperaturc, 9 g of furfural was added dropwise with stirring. Potassium 3-(2-furfurylidene)-2-methyl-dithiocarbazate was formed during stirring for 2 hours at room temperaturc. 100 ml of ether was added~ the suspension was cooled below 10 and the product was filtered off, washed with chilled ether and dried. 12 g of this product was sus-pended in 150 ml of methanol and 19 g of dimethyl sulphate - was added and the mixture was stirred for 5 hours at rGom temperature. Water was then added to 500 ml and after stirring for 15 minutes and cooling below 10, the product was filtered off and washed with water. The product had a m.p. of 103 and was identified as being S-methyl-3-furfurylidene~
2-methyl-dithiocarbazate.
,~, 15 Example 11 9.8 g methyl hydrazine was stirred with 70 mls absolute ethanol. 19.2 g furfural was added dropwise to the reaction mixture~ and stirred at room temperature for 12 hours.
10.8 g potassium hydroxide (dissolved in 40 mls ethanol) I 20 was added all at once~ and then 15.2 g carbon disulphide `i added dropwise (15C).
The reaction mixture was stirred at room temperature for 16 hours, cooled to 10C for 12 hours and filtered. A
¦ product with mp 237 was obtained and this was identified by spectroscopic means to be potassium 3~(~-furfurylidene)-2-, .. . .

.

.. . .

1075Z4~

mct;hyl-dit~lioc.lrbazate .

~--CI~0 + l~2NN~IC~13 ~ ~ CH=NN~ICH

Q CH--NNCS.K
Cll

4.8 g of this salt was dissolved in 50 ml of 50% aqueous ethanol then 2.52 g of dimethyl sulphate was added dropwise over 1 hour and further stirred for 2 hours. After cooling below 10 the product was filtered off~ washed in the chilled ethanol and dried. It was identified by spectroscopic means to be S-methyl 3-furfurylidene-2-methyl-dithiocarbazate.
; Exa ~
1 g of 2-(2-furyl)-4-methyl-1~3,4-thidiazolidine-5-thione was dissolved in 50 ml of warm ethanol~ and after cooling to room temperature 1.26 g of dimethyl sulphate was added. After stirring for 2.5 hours at 50~ o.69 g potassium was added~ the mixture was heated for 1.5 hours at 50~ then allowed to ~tand overnight. The reaction mixture was filtered and the filtrate was evaporated to dryness. The residue was re~rystallised from ethanol and pure S-methyl 3-furfurylidene-1 2-methyl-dithiocarbazate (mp = 103) was obtained.

:, :, . , . ~ .
.
,

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. S - methyl 3-furfurylidene-2-methyl-dithiocarbazate.

2. A process for the preparation of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate as claimed in Claim 1 which comprises a) treating 2-furfuraldehyde with S-methyl 2-methyl dithiocarbazate; or b) treating a salt of 3-(2-furfurylidene)-2-methyl dithiocarbazate with dimethyl sulphate; or c) treating 2-(2-furfuryl)-4-methyl -1,3,4-thiadia-zolidine -5-thione with dimethyl sulphate.

3. A method of treating seeds comprising applying to the seeds prior to sowing a fungicidally effective amount of the compound as claimed in Claim 1.

4, A method of treating seeds as claimed in Claim 3 wherein the seed is a cereal infected with Tilletia sp. and wherein the weight of S-methyl 3-furfurylidene-2-methyl-dithio-carbazate deposited on the surface of the seed is in the range from 50 to 1500 ppm of the weight of the seed,

5. A method of treating seeds according to Claim 4 wherein the weight of S-methyl 3-furfurylidene-2-methyl-dithiocarbazate deposited on the surface of the seed is in the range of from 230 ppm to 1500 ppm of the weight of the seed.

6. A method of controlling foliar fungi on plants by spraying the foliage of said plants with a fungicidally effective amount of the compound as claimed in Claim 1.

7. A method as claimed in Claim 6 wherein the plants are infected with one of the following fungus diseases:
Puccinia coronata, Rhizoctonia solani, Ceratocystis poradoxa and Venturia inequalis.