DE954596C - Process for the production of fungicides and insect repellants of the crotonic acid amide and ª ‰ -Methylcrotonic acid amide series - Google Patents

Description

Process for the preparation of fungicides and insect repellants of the crotonic acid amide and ß-methylcrotonic acid amide series It has been found that the crotonic acid and ß-methylcro @ tonsamic acid amides of the general formula where Ri is hydrogen or the methyl radical, R2 is an alkyl radical, R3 is a halogen atom or an alkoxy radical and R4 is hydrogen, the methyl radical or a halogen atom, are valuable fungicidal agents and insect repellants. In US Pat. No. 368,195, crotonic acid amides have been proposed as synergies for pyrethrum extracts. These compounds, when used alone, have an insufficient insecticidal effect. It could not be foreseen that a group of crotonic acid or. ß-methylcrotonic acid amides, which are not listed by name in the USA patent, have an excellent fungicidal and insect-repellent effect.

Various processes known per se can be used to prepare the defined amides. For example, a, ß-unsaturated carboxylic acids of the formula (I) or their reactive functional derivatives, such as halides, anhydrides, esters, amides or salts with substituted i, T-alkyl-anilines of the formula (II) or their salts, metal compounds or reactive derivatives.

This reaction takes place in principle according to the following reaction scheme In the above formulas, R1, R2, R3 and R4 have the meaning defined above, while X and Y denote radicals which are split off during the reaction.

In the simplest case, the free acid is heated with the amine, whereby water is split off (X = OH, Y = H, XY = H.0). It is also possible, for example, to react an alkali salt of the acid with a salt of the amine by heating (e.g. X = O Na, Y = H Cl - H, XY = Na Cl - I - H 2 O). Acid halides or anhydrides can be reacted with the amine, if appropriate in the presence of acid-binding agents, for which the amine itself can also be used (e.g. X = Cl, Y = H, XY = -H Cl). Furthermore, acid halides or anhydrides can also be reacted with metal compounds of the amines (e.g. X = Cl, Y = Na, XY = NaCl) or, in special cases, acid halides with halogen hydrates of the amines (e.g. X = Cl, Y = H Cl - H, XY = 2 HCl). Esters react with the amines with elimination of alcohols (e.g. X = OC H3, Y = H, XY = HOC H3) and finally amides also react with the N-alkyl-arylamines or their salts, releasing ammonia or ammonium salts (e.g. X = N H21 Y = H, XY = NH3).

A preferred embodiment, also according to the above reaction scheme runs, and which leads to halogen-free end products in particularly good yield, is the conversion of salts of acids with reactive carbamic acid derivatives, which are derived from the amines defined above. For example, carbamic acid halides, which can also be regarded as chloroformic acid derivatives of N-alkyl-arylamines, with alkali salts of α, ß-unsaturated acids by heating with elimination of Convert carbon dioxide and alkali halide to the desired amides (e.g. X = O Na, Y = CI-CO-, XY = NaCl -I- CO2).

The listing of these embodiments does not make any claim Completeness. The reactions can otherwise be as described in the literature Methods are carried out (see e.g. Weygand: Organic-chemical experimental art, e.g. Edition, z938, p. 38r).

Instead of a, ß-unsaturated carboxylic acids of the formula starting out, one can, for example, also start from corresponding, suitably substituted, saturated acids which can be used for the preparation of the α, ß-unsaturated acids, these z. B. in analogy to the explained whites in the Säu.reamide, and then form the double bond according to the methods customary for the production of α, ß-unsaturated acids (cf. Weygand, p.416). This process can be illustrated in principle by the following reaction scheme In this reaction topic, R1, R2, R3 and R4 have the meaning defined at the beginning, while X and Y in the reaction jointly denote radicals which are split off as XY.

This process is illustrated, for example, by the following possibilities: a) elimination of water from corresponding α- or β-oxysäureamidqn, according to the above reaction scheme in the first case X = H and Y = O H, in the second case X = OH and Y = H. The elimination of water can be carried out by heating, if appropriate in the presence of catalysts such as iodine or of dehydrating agents such as sulfuric acid, sodium bisulfate, oxalic acid, phosphorus halides, zinc chloride, etc. The easily accessible β-oxy acid derivatives are particularly suitable for this purpose. You can z. B. ß-Oxy-isovaleric acid- \ T-methyl-o-chloranilide by heating with dehydrating agents in ß, ß-dimethyl-acrylic acid-l, T-methyl-o-chloranilide.

b) The hydroxyl group of the oxyamides can also be mixed with an acid be esterified. In this case the formation of the double bond accomplished by splitting off a molecule of acid, be it by heating or Treat with an acid-binding agent. For example, ß-Benzoyloxy-butyric acid becomes N-methyl-o-chloroanilide Benza ° acid is split off by heating to form crotonic acid-N-methyl-o-chloroanilide. In this case, X = O C O C. H5 and Y = H.

c) The elimination of hydrogen halide from the corresponding a- or β-Halo, enoic acid amides (e.g. X = H or Cl, Y = Cl or H) is the one mentioned above Elimination of water from α- or ß-oxy-acid amides is quite analogous. The elimination of hydrogen halide is mostly done by treating with acid-binding agents, such as alkalis or tertiary Amines, e.g. B. Dim-ethylaniline or quinoline carried out. Is particularly suitable the elimination of hydrogen halide from a-halo acid amides, because these a-halo acid derivatives are easily accessible. For example, a-bromo-butt-, acid bromide is used with N-methyl-o-chloroaniline converted in the cold to a-bromo-buttersäu.re-N-methyl-o-chloroanilide, which in the Heating with dimethylaniline converts into the crotonic acid-methyl-o-cliloranilide.

Amides of the formula where Z denotes a group which can be replaced by hydrogen, and replace the group Z in these with hydrogen.

The group Z can mean, for example, a carboxyl group which is easily split off in the form of carbon dioxide on heating. Starting materials of this type can be prepared, for example, by reacting amines of the formula (II) with alkylidene-malonic acid derivatives of the formula wherein R1, as defined above, and Z is a carboxyl group or a radical which can be converted into the carboxyl group by saponification, such as the carbalkoxy or the -C N group, or by reaction with reactive derivatives of such acids. Subsequently, the radical Z is converted into the carboxyl group by saponification and this is split off at the same time or subsequently.

For example, isopropylidene malonic ester chloride is combined with an N-alkylarylamine of formula (II) converted to isopropylidene malonic ester-j \ -alkyl-arylide. In this the ester group can be converted into a free carboxyl group with hydrolyzing agents saponify. The isopropylide n-malonic acid mono-N-alkyl-arylide cleaves when heated Carbon dioxide, the corresponding ß, ß-dimethylacrylic acid-N-alkylary li.d arises.

The group Z can also mean an acetyl group.

Am.ide of the formula which are obtainable, for example, from alkylidene-acetic acid ethers and substituted N-alkyl-anilines, give the desired anilides on hydrolysis.

One can also use amides of the formula where 1z1, 1z2, R3 and R4 correspond to the definition given at the beginning, e.g. B. produce analogously to one of the methods described and explained above and alkylate the amides obtained on nitrogen.

The methods known per se can be used for the alkylation, e.g. B. dialkyl sulfates, alkyl halides or aryl sulfonic acid alkyl esters can be used as alkylating agents (cf., for example, Titherley, - J. chem. Soc., London 79, p. 391 [190i]).

In the following examples, which are described to illustrate the To serve processes, parts always mean parts by weight. The temperatures are given in degrees Celsius.

Example i 1o, 5 parts of crotonic acid chloride are added with stirring 28.5 parts of N-methyl-o-chloroaniline are added dropwise so that the temperature drops to 13o to 14o ° increases. After cooling, the reaction product is mixed with ether or another Water immiscible solvent and the solution successively with hydrochloric acid, Washed lye and water. After the solvent has been distilled off, the residue becomes distilled in vacuo. The crotons, acid-N-methyl-o-cliloranilid boils below 13 mm print at 169 to 173o.

Example e 14.6 parts of ß-oxy-isovaleric acid-ethyl, ester are with 14.2 parts of N-methyl-o-chloroaniline until the elimination of alcohol has ended heated to about 16o °. After cooling, sodium hydrogen sulfate is added and the mixture is heated briefly to igo to 20o ° and the dimethylacrylic acid-N-m @ ethyl-o-chloroanilide formed is distilled in a vacuum. It boils under 13 mm pressure at 168 to 172 ° and turns yellowish Oil.

According to the above examples and the other methods given in the description, for. B. the following connections can also be shown: Boiling point pressure Crotonic acid-N-ethyl- p-bromanilide .......... 127 to 13o ° 0.1 mm Crotonic acid-N-ethyl- 3, 4-dichloroanilide ...... 138 to 141 ° o, i mm Crotonic acid-N-ethyl- 2-chloro-6-methylanilide. . 118 to 121 '0.05 mm Crotonic acid-N-methyl- p-anisidid ............. 135 to 14o ° 0.1 mm Crotonic acid-N-ethyl- o-anisidid ............. 133 to i38 ° 0.15 mm Crotonic acid-N-ethyl- p-phenetidide. .......... 143 to 147 ° o, 1 mm ß-methylcrotonic acid N-ethyl-p-bromanilide .. 121 to 126 ° o, i mm / 3-methylcrotonic acid N-ethyl-m-chloroanilide. . 114 to 116 ° o, o5 mm ß-methylcrotonic acid N-ethyl-3, 4-dichloro anilide ................. 123 to 126 ° 0.05 mm ß-methylcrotonic acid N-ethyl-2-chloro-6-methyl- anilide ................. 117 to 118 '0.5 mm ß-methylcrotonic acid N-ethyl-o-anisidide ..... 126 to 130 ° 0.2 mm ß-methylcrotonic acid N-methyl-p-anisidide ... 134 to 138 ° 0.1 mm ß-methylcro @ onic acid N-ethyl-p-phenetidide ... 143 to 1q.8 ° 0.2 mm

Claims (4)

PATENT CLAIMS: 1. Process for the preparation of fungicides and insect repellants of the Cro.tonsäureamid- and ß-Methylcrotonsäureamid series, characterized in that substituted N-alkylanilines of the general formula where R2 is an alkyl radical, R3 is a halogen atom or an alkoxy radical and R4 is hydrogen, a halogen atom or the methyl radical or their salts, metal compounds or reactive derivatives with acids of the general formula where R1 is hydrogen or the Mephyl radical, their reactive functional derivatives, such as halides, anhydrides or salts, or with saturated aliphatic carboxylic acids or their reactive functional derivatives, which can be converted into one of the two acids defined above, optionally in the presence of condensation or acid-binding agents, in a manner known per se in amides of general formula R CH, -C = CH-CO -N- ' @ R4 Rz R2 convicted. 2. The method according to claim i, characterized in that one reactive Carbamic acid derivatives, such as carbamic acid halides, which differ from substituted Derive N-alkylanilines of the formula defined in claim i, with salts of acids implements the formula defined in claim i. 3. The method according to claim i, characterized in that substituted N-alkylanilines of the formula defined in claim i or their salts, metal compounds or reactive derivatives with saturated carboxylic acids of the formula in which X and Y together denote radicals which can be split off and R1 has the meaning given in claim i or acylated with its reactive derivatives and in the resulting saturated substituted anilides of the formula the double bond is produced by joint cleavage of the radicals X and Y in a manner known per se. 4. The method according to claim i, characterized in that substituted N-alkylanilines of the formula defined in claim i or their salts, metal compounds or reactive derivatives with carboxylic acids the formula I. CH3-C = C-COOH R1 in which Z is a carbalkoxy, cyano or acyl group and R1 has the meaning given in claim i or acylated with its reactive functional derivatives and in the substituted anilides of the formula obtained the carbalkoxy or cyano group is replaced by saponification and decarboxylation or the acyl group is replaced by hydrogen by saponification. Process according to Claim r, characterized in that a substituted aniline of the formula wherein R3 and 'R4 have the meaning given in claim z or their salts, metal compounds or reactive derivatives are acylated with acids of the formula defined in claim r or with their reactive functional derivatives, and the substituted anilides of the formula obtained alkylated on nitrogen in a manner known per se.