DE1037465B - Process for the preparation of homochromanone derivatives with insecticidal and herbicidal effects - Google Patents

Description

Process for the preparation of homochromanone derivatives with insecticider and herbicidal activity The invention relates to a method for producing halogen-substituted homochromanone derivatives.

It is already. known, y-phenoxybutyric acids, which are also essentially alkyl or can be alkoxy-substituted by treatment with phosphoric acid and phosphorus pentoxide to convert with ring closure in Ho.mochromanonderivate (cf. Annalen der Chemie 587, pp. 38 to 50). It has now been found that new compounds with excellent herbicidal and insecticidal effects, if one works with the known method of γ-phenyloxybutyric acid which is halogen-substituted in the core and optionally also alkylated goes out. These compounds are previously known compounds of this series superior in their insecticidal and herbicidal effectiveness and proven in Concentrations on the order of 10-3g / ccm are found to be effective against house flies (musca domestica). The kill was 100% after 24 hours. In contrast, Rotenone showed an insecticide only in concentrations of 10-1 g / ccm with the same experimental set-up Effect. Moreover, the connections can be made in a simple manner and in part abundant existing and cheap raw materials, e.g. B. the secondary isomers of y-hexachlorocyclohexane, getting produced. The fluorine-containing homochromanone derivatives have proven to be particularly effective proven to have germicidal properties at the same time. Here could be the lower Limit of effectiveness a concentration of 5 - 10-5 g / ccm can be determined.

EXAMPLE 1 35.6 g of 2-methyl-4-cblophenol are prepared in a known manner This is done accordingly by adding 470/0 sodium hydroxide solution and draining in vacuo substituted phenolate, which is then added in a known manner with 22.6 g of butyrolactone is converted to y- (2-methyl-4-chlorophenoxy) butyric acid.

50 g of the free acid are mixed with 120 g of phosphoric acid (d = 1.7) and 220 g of phosphorus pentoxide and heated to 80 to 110 ° C. for 2 hours with stirring. The reaction mixture is allowed to cool and poured onto crushed ice. Then it is stirred with a benzene-ether mixture, the resulting solution of the homochromanone derivative is washed with dilute sodium hydroxide solution in order to recover the unreacted acid, dried with molten calcium chloride, freed from the solvent and the residue is distilled in vacuo. The reaction product passes between 175 and 177 ° C. at 12 mm mercury pressure and can optionally be recrystallized from methanol. The melting point of 7-chloro-9-methylhomochromanone is 68 ° C. Example 2 1,2,4-Trichlorobenzene, which can be obtained from the secondary isomers of γ-hexachlorocyclohexane, is converted in a known manner by chlorination into tetrachlorobenzene and by subsequent saponification into 2,4,5-trichlorophenol.

The sodium salt of 2,4,5-trichlorophenol is obtained in a known manner from a mixture of 49.2 g of 2,4,5-trichlorophenol, 50 ccm of xylene and 21.3 g of a 471% sodium hydroxide solution by azeotropic distillation of the water as dry , obtained fine powder and then reacted in a known manner with 22.6 g of butyrolactone in vacuo to give y- (2,4,5-trichlorophenoxy) butyric acid. In accordance with Example 1, 6,7,9-trichlorohomochromanone is obtained in a yield of 40% of theory from the free acid after boiling for 4 hours with a mixture of 120 g of phosphoric acid and 220 g of phosphorus pentoxide. Example 3 1,2,4-Trichlorobenzo is saponified in a known manner to give 2,5-dichlorophenol. 41 g of this compound are converted according to Example 1 into the sodium salt and then into the γ- (2,5-dichlorophenoxy) butyric acid. The ring closure takes place here in 35% yield to 6,9-dichlorohomochromanone. Example 4 28.0 g of p-fluorophenol are converted in a known manner into the phenolate according to Example 1, which is then reacted in the known manner with 22.6 g of butyrolactoti. The resulting sodium salt of γ- (4-fluorophenoxy) butyric acid is taken up in water and the free acid is precipitated by adding dilute sulfuric acid.

20 g of y (4 = fluorophenoxy) butyric acid «earths are treated with a mixture of 50 g of phosphoric acid and 100 g of phosphorus pentoxide for 2 to 3 hours at 80 to 110 ° C. After working up, the 7-fluorohomochromanone is isolated in a yield of 40% of theory.

Claims (1)

PATENT CLAIM: Process for the production of homoehromanone derivatives with insecticidal and herbicidal action, characterized in that the core ' halogenated and optionally also alkylated γ-phenyloxybutyric acids in an known way by treatment with a mixture of phosphoric acid and phosphorus pentoxide closes to the ring.