Otsuka Chemical Co., Ltd.

Otsuka Kagaku Yakuhin Kabushiki Kaisha

Yuzuru Ogata

Masayoshi Suzue

Tsukuru Kinoshita

Hideo Tanaka

Sigeru Torii

Michio Sasaoka

Norio Saito

Yoshifumi Nakacho

Shigemitsu Nagao

Toshio Fukuhara

Shigeru Araki

A process for preparing an azetidinone derivative represented by the formula (I) ##STR1## wherein R.sup.1 represents an aryl group, arylmethyl group or aryloxymethyl group, R.sup.2 represents hydrogen atom or a carboxyl-protecting group and R.sup.3 represents an alkyl group or aryl group, the process comprising reacting an azetidinone derivative represented by the formula (II) ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above with a chlorinating agent.

Halogenation process for preparing

A process for separating cyclic phosphazene oligomers from a mixture containing cyclic phosphazene oligomers and linear phosphazenes by bringing the mixture into contact with a mineral adsorbent composed of mainly silicon and/or aluminum and removing the adsorbent. Cyclic phosphazene oligomers of high purity can be readily separated in high yields by the process.

Process for separating cyclic phosphazene oligomers

An improved process for preparing tri- and tetraphosphonitrilic chlorides in a shortened period of time in high yields by reacting ammonium chloride with phosphorus pentachloride produced simultaneously with the progress of the reaction from phosphorus trichloride and chlorine, in an organic solvent inert to chlorine in the presence of a catalyst, while adding dropwise phosphorus trichloride and supplying chlorine gas to the reaction system.

Process for preparing crystalline phosphonitrilic chloride oligomers

A process for preparing tri- and tetra-phosphonitrilic chlorides in a shortened period of time in high yields by reacting ammonium chloride with phosphorus pentachloride in an organic solvent inert to chlorine in the presence of at least one catalyst selected from metal oxides of Groups II-A, II-B, III-A, IV-A, IV-B and VIII of the Periodic Table, metal sulfides, metal salts of fatty acids, metal complexes, organometallic compounds and metal peroxides of Groups II-A and II-B of the Periodic Table, metal hydroxides of Groups III-A and VIII of the Periodic Table, and magnesium hydroxide. Phosphorus pentachloride may also be produced simultaneously with the reaction by reacting phosphorus trichloride employed instead of phosphorus pentachloride with chlorine gas supplied into the reaction system, or by previously reacting phosphorus employed instead of phosphorus pentachloride with chlorine gas supplied into the reaction system to produce phosphorus trichloride and then reacting phosphorus trichloride with chlorine gas in the same manner as in the case using phosphorus trichloride as the starting material.

A composition for inhibiting the growth of plants comprising:

Growing community of inventors

Tokushima, Japan

Yuzuru Ogata