Denki Kagaku Kogyo Kabushiki Kaisha

Rikagaku Kenkyusyo

Seiichi Watanabe

Higashi Ito

Itsuo Tabata

Takashi Kadowaki

Takao Iwasaki

Chiyuki Fujii

Koichi Abe

Masayuki Shinoyama

Michio Nishimura

A complex of an electron-attracting group-substituted .eta..sup.5 -cyclopentadienylcobalt with a polyene or an acetylene for use as a catalyst, for example, for the synthesis of a substituted pyridine from an alkyne and a nitrile.

Substituted cyclopentadienyl cobalt complexes and synthesis of pyridine

Chloroprene is produced by reacting 3,4-dichlorobutene-1 in an aqueous solution of an alkali metal hydroxide in the presence of at least one of furfuryl alcohol and tetrahydrofurfuryl alcohol preferably at 20.degree. to 70.degree. C.

Process for producing chloroprene

Chloroprene is produced by a dehydrochlorination of 3,4-dichlorobutene-1 by contacting 3,4-dichlorobutene with a metal alkoxide of tetrahydrofurfuryl alcohol. The reaction mixture in a form of a slurry obtained by the dehydrochlorination is distilled to separate lower boiling components comprising chloroprene and the unreacted 3,4-dichlorobutene-1 as main components from higher boiling components comprising tetrahydrofurfuryl alcohol and a metal chloride as main components.

3,4-Dichlorobutene-1 and 1,4-dichlorobutene-2 are isomerized in the presence of a catalyst of a combination of a copper compound or copper metal and at least one additive from the group of 1,3-diphenylguanidine, di-o-tolylguanidine, glycine ethyl ester hydrochloride and 2-amino-4-chlorophenol.

Isomerization of dichlorobutenes

An isomerization between 3,4-dichlorobutene-1 and 1,4-dichlorobutene-2 is carried out in the presence of a catalyst for isomerization as a combination of a copper compound and a dithiocarbamic acid derivative. The dithiocarbamic acid derivative is a compound having the formula ##STR1## wherein R and R' are the same and different and respectively represent a C.sub.1 -C.sub.8 alkyl group or an aryl group and M represents hydrogen atom or a metal atom or ammonium group and R' represents a C.sub.1 -C.sub.8 alkyl group, an aryl group or a heterocyclic group such as mercaptobenzothiazole.

Chloroprene having a little content of acetaldehyde is produced by dehydrochlorination of 3,4-dichlorobutene-1 in the presence of an aqueous solution of an alkali metal hydroxide by treating with an ammonium ion donor during or after the dehydrochlorination or in both the steps.

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Ohmi, Japan

Seiichi Watanabe