Sumitomo Chemical Company, Limited

Akio Higo

Nobushige Itaya

Nobuo Ohno

Masato Mizutani

Yoshitoshi Okuno

Yukio Suzuki

Fukashi Horiuchi

Hajime Hirai

Toshiko Honda

Akira Toyoura

A process for racemization of optically active phenylacetic acid derivatives, which comprises heating an optically active phenylacetic acid derivative of the formula (I): ##STR1## wherein X and Y, which may be the same or different, each represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a halogen-substituted lower alkyl group or a halogen-substituted lower alkoxy group, or X and Y may jointly form an alkylenedioxy group; m and n, which may be the same or different, each represents an integer of 1 to 5, and the sum of m and n does not exceed 5; and R represents an isopropyl group or a cyclopropyl group, to a temperature of at least 150.degree. C. in the presence or absence of an inert solvent.

Racemization of optically active

A purification process for 3-phenoxybenzaldehyde, which comprises reacting crude 3-phenoxybenzaldehyde with an alkali metal or ammonium bisulfite, or metabisulfite in the presence of an organic quaternary ammonium salt, an inorganic acid salt of organic tertiary amines, or a macrocyclic polyether used as a catalyst, isolating the resulting 3-phenoxybenzaldehyde alkali metal or ammonium bisulfite adduct, and decomposing it by using an acid or a base, or by heating.

Purification process for 3-phenoxybenzaldehyde

A novel process for preparing cis-chrysanthemic acid comprising (1) hydrolysis of trans-.delta.-halogenodihydrochrysanthemic acid or ester thereof under neutrally kept condition with an alkaline earth metal carbonate, (2) conversion of the obtained trans-.delta.-hydroxydihydrochrysanthemic acid ester into a mixture of cis-chrysanthemic acid and iso-cis-chrysanthemic acid by reacting with a strong base, and (3) separation of the cis-chrysanthemic acid from the mixture by selective conversion of the iso-cis-chrysanthemic acid with water in the presence of an acid catalyst into cis-dihydrochrysanthemolactone, followed by separation of the cis-chrysanthemic acid from the lactone with a caustic alkali and an acid. The present process is very useful for converting (-)-trans-chrysanthemic acid which is obtained, as a main remainder of racemic chrysanthemic acid prepared industrially, after (+)-trans-chrysanthemic acid was used for preparation of (+)-trans-chrysanthemic acid ester having a high insecticidal activity, into (+)-cis-chrysanthemic acid which is industrially valuable for preparation of insecticides.

Process for preparing cis-chrysanthemic acid

An insecticidal composition containing as an active ingredient an insecticidally effective amount of 10 to 30 % by weight of (+)-cis- and 70 to 90 % by weight of (+)-trans-chrysanthemate of the formula ##EQU1## wherein R is ##SPC1## In which R.sub.1 is an allyl or propargyl group, R.sub.2 is a propargyl, benzyl or phenoxy group, R.sub.3 is a hydrogen atom or a methyl group, R.sub.4 is a hydrogen atom or an ethynyl group and Y is an oxygen atom or --CH=CH-- group; and An insecticidal composition containing as an active ingredient an insecticidally effective amount of (a) at least one of above-mentioned (+)-cis,trans-chrysanthemates having said cis to trans ratio and (b) at least one of chrysanthemates prepared from a chrysanthemic acid having a cis to trans ratio different from that of the (+)-cis,trans-chrysanthemic acid moiety of the above formula (I) and an alcohol moiety of the above formula (I) having a structure different from that of the alcohol moiety of the (+)-cis,trans-chrysanthemates of above (a). The (+)-cis,trans-chrysanthemates having said cis to trans ratio show an excellent insecticidal effect as well as a strong synergistic effect on the chrysanthemates of above (b).

Growing community of inventors

Nishinomiya, Japan

Akio Higo