DE2136924A1 - PROCESS FOR THE PREPARATION OF 4-CHLORINE SUBSTITUTED BENZTHIAZOLES - Google Patents

Description

Process for the preparation of 4-chloro-substituted

The present invention relates to a chemically peculiar one Process for the preparation of new 4-chloro-substituted benzothiazoles. The substances as such and their use than fungicides and bactericides are part of another protective

desire (see German patent application P

(Le A 13 729) from the same date of submission).

The preparation of the new 4-chloro-substituted benzothiazoles cannot be accomplished by generally known processes. In particular, those benzothiazoles which have a negative substituent in the 7-position cannot be reacted directly with chlorine. It is only "known that heteroaromatic N-oxides can be converted by reaction with sulfuryl chloride or phosphorus oxychloride in compounds in ^ L and 'i-position to the N-oxide group are chlorine-substituted (see. E. Ochiai," Aromatic Amine Oxides ", pp. 184-200, Elsevier Publishing Company, Amsterdam / London / New York (1967)).

Le A 13 553

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It has now been found that the new 4-chloro-substituted Benzthiazoles of the formula

Cl

(D

in which

R stands for the CN group and the radical -CO-Z,

R stands for halogen, nitro, trifluoromethyl, trifluoromethoxy and the radical -SO ₀ -Y,

2
R stands for hydrogen, alkyl with up to 4 carbon atoms, for the CN group and for the radical -CO-Z and

can also have the meanings listed under R,

where the radicals Y and Z stand for hydrogen, alkyl, cycloalkyl and alkoxy each with up to 6 carbon atoms, furthermore for aralkyl, aryl and for the group / ^R 3 and ~ _x

R and R for hydrogen, alkyl and alkoxyalkyl with each up to 12 carbon atoms, for alkenyl with up to 4 carbon atoms, for phenylalkyl and stand for phenyl, the phenyl radicals being replaced by chlorine, Bromine, trifluoromethyl and methyl can be substituted,

3 4
Furthermore, R and R together with the connected nitrogen atom can form a 5- or 6-membered ring, which can optionally contain oxygen or sulfur or the N-alkyl group in the ring as further heteroatoms,

Le A 13 553

-Z-

2 96

obtained by benzothiazole N-oxides of the formula

(II)

in which

1 2
R, R and R have the meaning given above,

with thionyl chloride in an inert solvent in the temperature range between 20 and 160 ° C.

It can be described as extremely surprising that the desired chlorination reaction can be brought about with thionyl chloride can, while on the other hand sulfuryl chloride by the benzothiazole N-oxides of the formula (II) in sulfur dioxide and Chlorine is split up and the reaction with phosphorus oxychloride leads to benzthiazolones (subject of the German Patent application P 21 51 154.1 dated November 12, 1971).

The inventive method is advantageous in that the benzthiazole N-oxides which can be easily prepared in a known manner from nitrobenzene derivatives and thioglycolic acid esters (cf. German Offenlegungsschrift 1 904 653) reacted in one reaction with deoxygenation and simultaneous chlorination to the 4-chloro-substituted benzothiazoles can be. '

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If you use 2-ethoxycarbonyl-benzothiazole-N-oxide and thionyl chloride as starting materials, the course of the reaction can be represented by the following equation:

Cl

CO-OC ₂ H ₅

+ SOCl ₂ -

SO ₂ + HCl

CO-OC ₂ H ₅

The benzothiazole N-oxides to be used as starting materials are defined by the general formula (II). In this formula, R preferably represents the cyano group and the remainder

-CO-Z, R preferably represents chlorine, bromine, nitro and

2 represents the trifluoromethyl group and the radical -SO ₂ -Y, R represents

preferably for methyl, ethyl, chlorine, bromine, cyano, trifluoromethyl and for the radical -CO-Z, Y and Z are preferably alkyl and alkoxy with up to 4 carbon atoms, for 'benzyl, Phenyl and the group -N “n3, R and R preferably stand represents hydrogen, alkyl and cycloalkyl with up to 6 carbon atoms, and R also preferably represents phenyl, moreover R and R can together with the connecting nitrogen atom preferably a pyrrolidine and piperidine ring and, with the inclusion of oxygen as a further hetero atom, one Form morpholine ring. The benzothiazole N-oxides and their master position are partly known (see German Offenlegungsschrift 1 904 653), and new compounds can be prepared in a similar manner to the previously known compounds from 1-halo-2-nitrobenzene derivatives and thioglycolic acid derivatives in water or organic solvents (e.g. in alcohol or benzene) in Presence of bases (e.g. triethylamine) can be obtained.

Le A 13 553

209885/1296

Inert organic solvents are suitable as diluents. These include hydrocarbons such as benzene, toluene, chlorinated hydrocarbons such as methylene chloride, chlorov form, carbon tetrachloride and ethylene chloride, ether ,, like Dioxane and nitriles such as acetonitrile.

The reaction temperatures can be in a larger range can be varied. In general, the temperature is between 20 and 160 ° C., preferably between 50 and 110 ° C.

The method is usually carried out so that the corresponding benzthiazole N-oxides of the general formula (II) in a suitable solvent in the specified temperature range with at least the equimolar amount of thionyl chloride reacted in portions and the reaction mixture stirred for some time at a higher temperature »If necessary, can Thionyl chloride alone can also be used as the reaction medium. The new 4-chloro-substituted ones formed during the implementation Benzthiazoles sometimes precipitate as colorless compounds during the reaction and can be used in the usual way Separated way and isolated after washing with water in pure form and in good yield. If necessary, that is To remove the solvent in vacuo and to treat the solid residue obtained as indicated above. For further cleaning the compounds can be recrystallized from organic solvents.

As mentioned at the outset, the substances which can be prepared according to the invention have a fungicidal and bactericidal activity. they are therefore particularly suitable for crop protection. The possible applications are based on the following examples emerge:

Le A 13 553 - 5 -

2 0 9 8 8 5/1 29 6

Example k: £

Agar plate test

Testing for fungitoxic effectiveness and the breadth of the spectrum of effects.

Solvent: parts by weight

Acetone: a) 1000

b) 100

To produce an appropriate preparation of active compound, 1 part by weight of active compound is taken in the stated amount of solvent on.

The active ingredient preparation is given to potato dextrole agar, the is liquefied by heating, in such an amount that the desired concentration of active ingredient is achieved therein. After thorough shaking to evenly distribute the active ingredient, the agar is poured in under sterile conditions Petri dishes. After the mixture of substrate and active ingredient has solidified, test mushrooms are made from pure cultures in discs of 5 mm in diameter. The Petri dishes remain for Incubate for 3 days at 20 ° C.

After this time, the inhibitory effect of the active ingredient on the Mycelial growth determined in categories taking into account the untreated control. 0 means no mycelial growth, neither on the treated substrate nor on the inoculum; - means mycelium growth only on the inoculum, no overgrowth onto the treated substrate; and + means mycelial growth from inoculum onto treated substrate, similar to overgrowth on the untreated substrate in the control.

Active ingredients, active ingredient concentrations, test mushrooms and the inhibitory effects achieved are shown in the following table:

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209885/1296

tr ¹ φ

VJl table agar plate test

CD CD OC

Active ingredient

Active ingredient conc. in the substrate in mg / liter • Η · Η
ϋ · Η

• Η CO

• Ρ «Η UH OO

Q U

co 3 • Η U Ö O • Η · Η -P -P OO in Sh Φ Q) HH O O

m co

CO • Η CO

Pt O

• Η cd

> Η

cd ο

H ϋ

ω η

• Η CO

• Η CQ

CD β • Η 3 Q P. S. • Η U ! η ρ " jL, P. P. ο CD O • Η O • Η ο CO B. P ₁ • ■ Ρ -P 3 H CD co CD «Η ϋ 3
ϋ CQ !>. co P ₁ CD
ο ο • Η ο Ö ■ Ρ CD H O
CO

untreated

S II

¹ CH ₉ -NH-CS-

CH ₀ -NH-CS 2! I

a)

10 100

-4 »

(known)

10 .0 0 0 0 100 0 0 0 0

CD NJl

Ir ¹ CD

Agar plate test table

VJl

Active ingredient

Active ingredient conc. in the substrate in mg / liter (continued)

u ο

U ft co w co! >>

approx

■ Η

P.

• Η · Η Sh Ö CtJ co Kl H cd O fo CQ

CO OC CD

b '

10 100

O O

O O

O O

03 I.

b '

10 100

O O

O O

O O

O ₂ ¹ J Cl

10 100

Example B:

Bacteria test / Xanthomonas oryzae

Solvent: 1.9 parts by weight of dimethylformamide. Dispersant: 0.1 part by weight of alkylaryl polyglycol ether Water: 38 parts by weight

Mix the for the desired concentration of active ingredient in the amount of active substance required for the spray liquid with the specified Amount of solvent and dispersant and dilute the concentrate with the specified amount of water.

30 rice plants about 30 days old are sprayed with the spray liquid until they are dripping wet. The plants remain in a greenhouse at temperatures of 22 to 24 ° C. and a relative atmospheric humidity of about 70% until they have dried. Then needles are dipped into an aqueous bacterial suspension of Xanthomonas oryzae and the plants are inoculated by piercing the leaves. After inoculation, the plants are in a room at 26 to 28 ° C. and 80 % relative humidity.

10 days after the inoculation, the infestation is determined in percent of the untreated but also inoculated leaves of the control plants in leaves that have been injured by sting alone, inoculated and previously treated with preparation. 0 % means no infestation, 100% means that the infestation is just as high as in the case of the control plants.

Active ingredients, active ingredient concentrations and results run out the table below:

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209885/1296

Tabel Bacteria test / Xanthomonas oryzae

Active ingredient attack in % of the attack on the untreated control at an active ingredient concentration (in %) of 0.05 0.025

Cl

CO-NH-C ₂ H ₅

F, C

NO.

Cl

CN

CF-. 50

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209885/1296

Production Examples: Example 1;

CO-OC ₂ H ₅

151 g (0.5 mol) of 2-ethoxycarbonyl-5-chloro-7-nitro-benzothiazole-N-oxide are suspended in 300 ecm of anhydrous toluene and reacted dropwise at 80 to 100 ° C. with 50 ecm of thionyl chloride. A clear reaction solution is formed with strong evolution of hydrogen chloride and sulfur dioxide. When the dropwise addition of the thionyl chloride is complete, the reaction mixture is stirred for a further 1 hour at 110 ° C. and then allowed to cool. After cooling, the separated colorless product is filtered off with suction and washed neutral with water. 107 g of 2-ethoxycarbonyl-4,5-dichloro-7-nitro-benzothiazole are obtained in the form of colorless, matted needles with a melting point of 195 ° -197 ° C. The yield is 67 % of theory.

Example 2;

Cl

CO-OC ₂ H ₅

168 g (0.5 mol) of 2-ethoxycarbonyl-5-trifluoromethyl-7-nitrobenzthiazole-N-oxide are reacted in 400 ecm toluene with 45 ecm thionyl chloride in the manner described in Example 1.

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209885/1296

The toluene is removed from the clear reaction solution in vacuo and the crystalline residue is redissolved from a little ethanol after washing with water. 120 g of 2-ethoxycart) onyl-4-chloro-5-trifluoromethyl-7-nitro-benzothiazole are obtained in the form of slightly yellowish crystals with a melting point of 99-100 ° C. The yield is 68 % of theory.

Example 3:

CONH ₂

306 g (1 mol) of Z-amidocarbonyl-S-trifluoromethyl-T-nitro-benzthiazole-N-oxide are reacted in 800 ecm of toluene with 120 ecm of thionyl chloride as in Example 1 and the mixture is stirred at 110 ° C. for 2 hours. After the reaction mixture has cooled down, the thick, colorless crystal slurry is filtered off with suction and washed neutral with water. After recrystallization from alcohol, 235 g of 2-aminocarbonyl-4-chloro-5-trifluoromethyl-7-nitro-benzothiazole are obtained in the form of almost colorless needles with a melting point of 208-209 ° C. The yield is 72 % of theory.

In an analogous manner, the following 4-chloro-substituted ones can also be used Represent benzothiazoles (the example number, formula, and physical properties are each given) :

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209885/1296

Cl

CO-OC ₂ H ₅

CF,

Mp 135-136 ° C

(5)

CH ₃ OOC

Cl

, N

NO,

CO-OC ₂ H ₅

Mp. 95 - 97 ^U C

(6)

Cl

NO.

CO-OC ₂ H ₅

Mp 224-226 ° C

CO-OC ₂ H ₅

Mp 203-204 ° C

(8th)
F ₃ C

Cl

Mp. 164-165 ° C (9)

Cl

I. N F, C I. N ■ sJk ,1 Λ CONHCH ₃ T
NO ₂ NO ₂

CONHC

3 ^H 7

M.p. 148-150 ° C

(10)
F ₃ C

Cl

NO,

CO-NH-IC ₃ H ₇

Mp. 108-110 ° C Le A 13

(11) Cl

F ₃ C

NO ₂ CO-NH-IC ₇₊ H ₉

M.p. 93-95 ^W C

- 13 -

209885 / 129ö

(12)

Cl

CF,

CONHC ₂ H ₅

M.p. 160-162 ° C (14)

Cl

Jl

'CONH,

NO,

M.p. 295-297 ° C

(16)

Mp 125-127 ° C

Cl

(18)

O ₂ N

CF ₃ m.p. 94-95 ° C

Le A 13

CN

(13) Cl

Cl

'CONHCH,

NO,

Mp. 238-240 ° C (15)

Cl

O ₂ N

CONHCH ₇

CF

M.p. 160-162 ° C

(17)

Cl

CN

NO,

M.p. 155-157 "C

(19)

Cl

CONH,

CF

Mp. 206-208 ° C.

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209885/1296

Claims (2)

Patent claims: R represents halogen, nitro, trifluoromethyl, trifluoromethoxy and the radical -SO ₅ -Y, p <- R for hydrogen, alkyl with up to 4 carbon atoms, stands for the CN group and for the radical -CO-Z and furthermore can also have the meanings listed under R, where the radicals Y and Z are hydrogen, alkyl, Cycloalkyl and alkoxy each with up to 6 carbon atoms, also for aralkyl, aryl and for the group - N stand and R ^ and R for hydrogen, alkyl and alkoxyalkyl with each up to 12 carbon atoms, for alkenyl with up to 4 carbon atoms, for phenylalkyl and for Phenyl, where the phenyl radicals are represented by chlorine, bromine, Trifluoromethyl and methyl can be substituted, furthermore R ^ and R together with the linked Nitrogen atom form a 5- or 6-membered ring, which optionally also contains oxygen as further heteroatoms or contain sulfur or the group N-alkyl in the ring can, Le A 13 553 - 15 - 209 8 8 5/1296 2E36924 with thionyl chloride in an inert solvent in the temperature range converts from 20 to 16O ° C. 2.) The method according to claim 1, characterized in that the U:
undertakes. the reaction in the temperature range between t> 0 and 110 ° C Le A 13 553 - 16 - 209885/1296