DE1235301B - Process for the preparation of N, N-dimethyl-N'-phenyl-N'-fluorodichloromethylthio-sulfamide - Google Patents

Description

JNDESKEPUBLIK GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German KL: 12 ο-23 ^ 03

- SO- Α / ζ

Number. 1235 3011

File number F 48568 Jv b / 12 ο

Registration date: March 3 ljp66

Display day: 2 May lj) 67

The present invention relates to a chemically peculiar method of making the already known, fungicidally active N, N-dimethyl-N'-phenyl-N'-fluorodichloromethylthio-sulfamide

It has already become known that the IS ^ N-dimethyl-N'-phenyl-N'-fluorodichloromethylthiosulfamide is obtained if Ν, Ν-dimethyl-N'-phenylsulfamide is reacted with dichlorofluoromethanesulfene acid chloride (cf. German Auslegeschrift 1193 498) m either an inert organic solvent ίο made or in the aqueous medium. In both cases, an acid binding agent such as alkali metal hydroxide, alkali metal carbonate or a tertiary amine is added in order to intercept the hydrogen chloride formed. The desired end product is obtained in a yield of about 54% (cf. German Auslegeschnlt 1193 498, Example 2) to use organic solvent and to separate the sulfamide from this solvent. In addition, the tertiary Amm could be replaced by alkali hydroxide. The recovery of a tertiary amine was thus omitted

If one tries now, the N, N-dimethyl-N'-phenyl-N'-fluorodichloromethylthio-sulfamide to be prepared by the known method in an aqueous medium, see above Yields of about 50 to 60% of theory are obtained. However, the reaction product is very impure and shows a wide melting range. In addition, sulfenchlond and decomposition products adhere to the product, which make the sulphamide smelly and foul make plant damaging. It is therefore necessary to subject the product to multiple cleaning operations. Only then do you receive a preparation a sharp melting point

The implementation of the reaction in aqueous Medium according to the known method therefore offers compared to carrying out in the presence of a organic solvents ultimately no V01 parts

It has also become known that the Implementation of imides with perchloromethyl mercaptan then the desired N-trichloromethylthioimide in high yield and particular purity is obtained when the reaction is carried out in an anhydrous organic solvents and using process for the preparation of N, N-Dimethy> N'-phenyl-N'-fluorordicMormpthylthio-sulfamide

Applicant |

Paint factories Bayer Aktiengesellschaft,
Leverkusen '

Named as the inventor

Dr Erich Klauke, Koln-Flitt ^ ird,

Dr Engelbert Kuhle, Bergiscji-Gladbach;

Dipl-Ing Dieter Pmkwart, ijColn-Stammheim -

a tertiary amine carried out as a saufebinder (see German layout 1 203 787)

This process also dispenses with the aqueous medium, although this is always technical in the Pnnpp Offers advantages With regard to a good product and high yields, you even work in one volhg anhydrous organic solvent

It has now been found that N, N-dimethyl-N'-phenyl-N'-fluorodichloromethylthjo-sulfamide is obtained in a technically simple manner, high yield and high purity if an aqueous solution of the calcium salt of Ν, Ν-dimethyl- p'-phenyl-sulfam.id at temperatures between 5 unp 25 ⁰ C and one

5 minutes under heated with fluoi-

dichloromethanesulfen chloride reacts and dea pH of the reaction solution by adding aqueous Holds alkali between 9.0 and 12.0

It is surprising that under the inventive conditions, the Ν, Ν-dimethyl-N'-phenyl-N'-fluorodichloromethylthio-sulfamide \ n gets high purity and in high yields Allerdmgs geling: this only stop if the specific conditions Reaktionsbedm If another salt is used in place of the calcium salt, the result will not be achieved

The following can be said of the individual reaction conditions

mean residence time from 1.5 to
vigorous mixing continuity:

The required calcium salt is 1
one N, N-dimethyl-N'-phenyl-sulfi
with the corresponding amount of Calcn
Calcium oxide dissolves in water
Place of the Calcmmsalzes the Natn
Potassium salt, one occurs largely
Reaction product is an it

made by putting together in the hydroxide or ■ one applies

malt or the decomposition of the

necessary that

one starts from the calcium salt

709 517/566

the calcium salt still has the advantage of being in Glass or enamel can work. Will the Fluorodichloromethane Sulfenchlond or if its reaction product is only partially hydrolyzed, it always arises a corresponding amount of hydrogen fluoride, which very quickly leads to the destruction of the vessel material If calcium ions are present, it is formed immediately the extremely difficult to dissolve calcium fluoride destruction of the vessel material is excluded, if for any reason small amounts of hydrogen fluoride should be formed

The reaction temperatures are 5-25 ° C, preferably between 12 and 17 ⁰ C, cherish At lower temperatures the conversion is too low, at higher temperatures already clearly em partial hydrolytic degradation occurs, whereby the yield considerably reduced.

The calculated mean usage time should be between 1.5 to 5 minutes, preferably between 2 and 4 minutes. Are the dwell times shorter, ao sales decrease significantly, while longer Dwell times, the quality of the end product immediately deteriorates significantly

It is also necessary that the reactants are mixed very well in the reaction vessel, otherwise the end product will clump together. The lumps absorb Sulfenchlond, which then becomes can decompose without reacting m the desired way.

The pH of the reaction mixture must be between 9 and 12, preferably between 10.3 and 10.8. If the pH drops significantly, ζ Β. below 7, there is no condensation at all instead of. The pH is expediently through Addition of aqueous sodium hydroxide solution or potassium hydroxide solution kept within the specified limits

If the reaction conditions according to the invention are adhered to it is possible that N, N-dimethyl-N'-phenyl-N'-fluorodichlomethylthio-sulfamide m yields of 85 to 90% and a purity of over 98% can be produced in a technically simple manner.

The purity of the product is practically as high as that of using anhydrous organic solvent manufactured product

According to a preferred embodiment, the continuous production of the sulfamide carried out so that in em reaction vessel of below is an aqueous solution of the calcium salt of N, N-dimethyl-N'-phenyl-sulfamide on the one hand and fluorodic-methanesulfen chloride on the other hand continuously initiates, the reaction mixture is stirred very vigorously and the reaction product from the upper part of the reaction vessel withdraws. The pH value is maintained by continuously adding aqueous sodium hydroxide solution in the desired area.

The withdrawn product is filtered. The desired N, N-dimethyl-N'-phenyl-N'- £ luordichloromethyl-thio-sulfamide is obtained directly as filter residue

example

By stirring equimolar amounts of calcium oxide and Ν, Ν-dimethyl-N'-phenylsulfamide in water, a solution is prepared which contains 1 mol of the sulfamide as calcium salt dissolved in 1.51. At a stirring speed of 1000 rpm, 35.6 kg (= 210 mol) of fluorodichloromethanesulfenchlond and 3231 (= 215 mol) of the prepared aqueous solution of the sulfamide are pumped through the reaction vessel from below in 3 hours carried out. This corresponds to an average usage time of around 3.1 minutes. The reaction temperature is kept ^{between 14 and 16 °} C. during the reaction by cooling with brine. In order to maintain the pH value of the solution 10.3 to 10.6, a total of 7 are kg of a 10 ° / ₀ aqueous solution of sodium hydroxide was added The discharged at the overflow suspension is suction filtered through eme suction filter, the filter residue is washed twice with methanol and dried. This gives 60.3 kg (= 86% of theory) of Ν, Ν-dimethyl-N'-phenyl-N'-fluorordicMoimethylthio-sulfamide with a degree of purity of over 98%.

Claims (1)

Claim: A process for the preparation of N, N-dimethyl-N'-phenyl-N'-fluorodichloromethylthio-suu * amide, characterized in that an aqueous solution of the calcium salt of N ₅ N-dimethyl-N'-phenyl-sulfamide is used at temperatures between 5 and 25 ° C and an average residence time of 1.5 to 5 minutes with vigorous mixing continuously with fluorodichloromethanesulfenechlond while maintaining the pH of the reaction solution by adding aqueous alkali between 9.0 and 12.0. 709 517/566 2 67 © Bundesdruckerei Berlin