DE1149350B - Process for the production of carbamic acid esters - Google Patents

Description

GERMAN

PATENT OFFICE

F34506IVb / 12o

REGISTRATION DATE: JULY 22, 1961

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL: MAY 30, 1963

The patent application F 31711 IVb / 12 ο concerns a process for the preparation of carbamic acid esters of the general formula

Process for the production of
Carbamic acid esters

Addition to patent application F 31711 IVb / 12o
(Interpretation 1145 162)

* VOC-NHCH ₃

Il ο

in which the dimethylamino group is in the m-position and R is a p-position methyl group or the dimethylamino group is in the p-position and R represents a methyl radical in the m-position, characterized in that corresponding dimethylaminophenols with methyl isocyanate, methyl carbamic acid chloride or with N-methyl phenyl carbamate be reacted or that dimethylaminophenyl chloroformate or carbonic acid bis (dimethylaminophenyl) ester reacts with methylamine.

As can be seen from the information in the aforementioned patent application, the methyldimethylaminophenyl-N-methylcarbamates are distinguished of the above general formula are characterized by a good insecticidal effectiveness and in this regard are the known 3-dimethylaminophenyl-N-methylcarbamate clearly superior. It has now been found that alkyl dialkylaminophenyl-N-methylcarbamates the general formula

Applicant:

Paint factories Bayer Aktiengesellschaft, Leverkusen

an excellent insecticidal effect, especially against caterpillars, flies, aphids and spider mites own.

In the above formula, Ri and R2 stand for lower alkyl radicals with 1 to 4 carbon atoms, while R _{3 stands for} a lower alkyl group with 2 to 4 carbon atoms.

Dr. Rudolf Heiss, Dr. Ernst Böcker,

Cologne-Stammheim,

and Dipl.-Landw. Dr. Günter Unterstenhöfer,
_a5 Opladen,

have been named as inventors

The invention relates to the production of such carbamic acid esters. It takes place in itself known methods.

Either the corresponding alkyl dialkylaminophenols reacted with methyl isocyanate or methyl carbamic acid chloride, or the aminophenols and phosgene mentioned are used first the chloroformic acid-alkyl-dialkylaminophenyl ester and lets the latter react with methylamine.

Furthermore, it is also possible from the bis (alkyldialkylaminophenyl) - to run out of carbonic acid esters and to react them with methylamine; Finally, the process products can by reacting with alkyl-dialkylaminophenylene N-methylphenyl carbamate can be obtained.

Compared to the well-known 3-dimethylaminophenyl-N-methylcarbamate show the carbamic acid esters obtainable according to the process a significantly better insecticidal effectiveness, as from the The test results compiled in the following table emerge:

309 598/33 «

3 Use against 4th the effect
Killing the
Pests in% link Caterpillars
(Plutella maculipennis)
Fruit flies
(Drosophila
melanogaster) Biologically
Active ingredient
concentration in% 100
0
0 / VOC-NHCH ₃
V ^ il
N °
/ \
CH ₃ CH ₃ Aphids
(Aphis fabae) 0.2
0.02
0.2 100
40 Spider mites
(Tetranychus telarius) 0.2
0.02 40 Caterpillars
(Plutella maculipennis) 0.2 100
100 CH ₃ ^ / ^^ O - C-NHCH ₃ Fruit flies
(Drosophila
melanogaster) 0.2
0.02 80 / ^N \
CH ₃ C ₂ H ₅ Aphids
(Aphis fabae) 0.2 100
100 Spider mites
(Tetranychus telarius) 0.2
0.02 100
40 0.2
0.02

The caterpillar tests were carried out in a known manner on cabbage leaves and the tests with flies carried out in closed rooms under the usual conditions while the results the aphid tests on French beans (Vicia faba) and those of the spider hood tests on French beans were determined.

The clear superiority of the product according to the invention over the analogue one ! »Known comparator preparation is from the specified Numerical values clearly visible. The following examples illustrate the claimed process:

example 1

CH ₃

C ₂ H ₅ C ₂ H ₅

In a manner analogous to that in Example 1, 17.5 g (0.1 mol) of 3-diethylamino-4-methylphenol are reacted and 6.3 grams (0.11 moles) of methyl isocyanate, 18.4 grams of 3-dietylanimo-4-methylphenyl-N-methylcarbamate obtain.

CHs

-C-NHCH ₃
O

16.5 g (0.1 mol) of S-methyl-ethylamino ^ methylphenol are dissolved in anhydrous benzene. This solution is initially mixed with 6.3 g (0.11 mol) Methyl isocyanate and then with 3 drops of triethylamine, whereupon a lively reaction below Heating of the mixture takes place. After standing for a day, the reaction mixture becomes benzene Solution washed with water, then dried over sodium sulfate and finally the solvent distilled off in vacuo. The residue left behind is 16 g of S-methyl-ethylamino- ^ methylphenyl-N-methylcarbamate from m.p. 68 to 69 ° C.

Claims (1)

PATENT CLAIM: Further development of the process for the preparation of carbamic acid esters of the 3 (4) -dimethylamino-4 (3) according to -methylphenols Patent Application F 31711 IVb / 12o, characterized in that in per se known manner Alkyldialkylaminophenole of the general formula in which Ri and R ₂ stand for lower alkyl radicals with 1 to 4 carbon atoms, while R _{3 stands for} a lower alkyl group with 1 to 4 carbon atoms, with methyl isocyanate or Methyl carbamic acid chloride or N-methyl phenyl carbamate implemented or that chloroformic acid-alkyl-dialkylaminophenyl ester the general formula ester of the general formula Ri - <) ^ O - C - O or bis (alkyl-dialkylaminophenyl) carbonic acid, in the latter two formulas Ri, R2 and R3 have the other meaning given above have to be reacted with methylamine.