DD242040A1 - NEW METHOD FOR THE PRODUCTION OF OXIM CARBAMATES - Google Patents

Abstract

The object of the invention - the phosgene-free presentation of this class of substances to reduce the technical effort is inventively by reacting dichloromethylenemammonium salts with oximes in an inert organic solvent and subsequent hydrolysis of the non-isolated Intermediate reached. The present invention representable compounds show some good herbicidal, insecticidal and acaricidal properties or can be used as antidotes.

Description

wherein R ¹ , R ^{2 have} the above meaning and X = Cl, SbCI ₆ and FSO ₃ , with oximes of the general formula III

CN

HONt / _ττι

^R \

wherein R ^{3 has} the above meaning, are reacted and thus worked phosgene-free according to the object of the invention.

2. The method according to item 1, characterized in that in an anhydrous, organic solvent which does not react with the salt Il and advantageously is not miscible with water and in the presence of HX-binding auxiliary bases (eg., Triethylamine, pyridine) is operated at room temperature.

3. The method according to item 1 and 2, characterized in that the resulting reaction product is not isolated, but hydrolyzed at room temperature and recovered after phase separation and drying from the solvent used according to claim 2 by concentration and recrystallization.

Field of application of the invention

Oxime Bamates of the general formula I.

Important technical products are surprisingly high in herbicides (cf., for example, US Pat. No. 3,482,346) or insecticidal and acaricidal action (cf., for example, DE-OS 2306277) or good potential applications as antidotes for protecting crops from aggressive ones Agrochemicals (cf., for example, DE-OS 2837204).

A large number of compounds of this class of compounds having various radicals R ¹ to R ^{3 have} already been synthesized and described in the patent literature.

Characteristic of the known technical solutions

The patent literature basically lists two methods for the synthesis of oxime carbamates of the formula I (cf., for example, DE-AS 2113752):

a) reaction of isocyanates with oximes

b) Reaction of carbamoyl chlorides or amine / phosgene mixtures with oximes.

Since both carbamoyl chlorides and isocyanates are generally prepared only by phosgenation of amines or their hydrochlorides, carbamates or N, N''-substituted ureas, the result is an above-average safety expense due to the high toxicity of the phosgene.

Object of the invention

The aim of the invention is the phosgene-free production of oxime carbamates of the formula I to reduce the technical complexity.

Explanation of the essence of the invention

The object of the invention is the preparation of oxime carbamates of the general formula I by reacting oximes with phosgene-free dichloromethyleneammonium salts (phosgeniminium salts) (compare Viehe, H.G., Angew. Ch. 85 (1973),

The object is achieved in that Dichlormethylenammoniumsalze the general formula II

Ί ^ Q _cl

\ n = c U

in which R ¹ and R ² independently of one another are lower-alkyl or substituted and unsubstituted phenyl radicals and X =Cl, SbCl ₆ and FSO 3, with oximes of the general formula III

CN

H-O-NaC ^/ , " ^I1Z

with R ³ = tert. Alkyl having 4-8 C atoms, methyl-substituted cycloalkyl having 5-7 C atoms, adamantyl and phenyl which may be optionally substituted with electron-withdrawing substituents (eg, Cl, Br, CF ₃ , CN) become. The resulting reaction product of formula IV

R ¹ 4 · / Cl

R ² 0-M = C ₃

is not isolated, but hydrolyzed in the reaction mixture to Oximcarbamat of formula I.

The reactions proceed in an anhydrous, organic solvent which is not allowed to react with the dichloromethyleneammonium salt (eg CH ₂ Cl ₂ ) and advantageously can not be mixed with water, expediently in the presence of HCl or HX-binding agents, such as eg triethylamine or pyrid + n.

The reaction proceeds at room temperature with gradual addition of the solution of oxime in the solvent-Z auxiliary base mixture to a suspension of the dichloromethyleneammononium salt in the appropriate solvent. The subsequent hydrolysis is also carried out at room temperature by stirring the reaction solution with water; the organic phase is separated, dried, concentrated and the crude product recrystallized.

embodiment

1) 2- (Dimethylaminocarbonyloxy) -2-phenylacetonitrile (Formula I where R ¹ = R ² = CH ₃ and R ³ = CeH ₅ ) To a suspension of 75 mmol dichloromethylenedimethylammonium chloride in 90 ml of dry dichloromethane are added 50 mmol of 2-hydroxyimino-2-phenylacetonitrile, dissolved in a mixture of 7 ml of dry pyridine and 20 ml of dichloromethane, added dropwise slowly with stirring at room temperature. After all the Dichlormethylendimethylammoniumchlorid has reacted, stirring is continued for a few minutes and then mixed with 50 ml of water. After brief stirring, the organic phase is separated, dried with CaCl ₂ , concentrated in vacuo and the crude product obtained from methanol / water recrystallized. 7,8g = 72% d. Th. Petals needles or platelets; F _p 82 to 83.5 ° C; ¹ H-NMR (CD ₂ Cl ₂ ) (IOOMHz): δ = 2.96 ppm (dublet, 6, (CH ₃ ) ₂ N-); δ = 7.4-7.9 ppm (multiplet, 5, C _e H ₅ ); IR: Yc = O = 1730 cm ^-1 JMSrM / = 217 (1.4%), B ⁺ = 72 (CH ₃ ) ₂ N -C = O ⁺ (100%)

Claims (1)

Invention claim: 1. A process for the preparation of oxime carbamates of the general formula I. wherein R ¹ and R ² independently of one another Niedrigalkyl- or substituted and unsubstituted phenyl radicals and R ³ = tert. Alkyl having 4-8 C atoms, methyl-substituted cycloalkyl - having 5-7 C atoms, adamantyl and phenyl - which may optionally be substituted by electron-withdrawing groups (eg Cl, Br, CF ₃ , CN), characterized in that dichloromethylenemammonium salts of the formula II