A method for producing an olefin oligomer is disclosed, in which an olefin oligomerization reaction is performed in the presence of an olefin oligomerization catalyst comprising (A) a chromium compound, (B) an amine compound of the general formula (1): ##STR00001##
(R.sup.1 to R.sup.4 represent a group such as a hydrocarbon group, Y represents a structure represented by —CR.sup.5R.sup.6—, R.sup.5 and R.sup.6 represent a group such as a hydrogen atom, and Z represents an integer of 1 to 10),
and (C) a compound such as an organometal compound; and the olefin oligomerization catalyst.

The present invention aims to provide a method by which fluorine-containing sulfide compounds, particularly sulfide compounds that contain hydrogen and fluorine, can be produced in a simple, low-cost and industrial manner. Provided is a method of producing a fluorine-containing sulfide compound represented by the following formula (2):
(F).sub.n-A.sup.3-S-A.sup.4-(F).sub.m  (2)
(wherein A.sup.3 and A.sup.4 are independently an optionally substituted hydrocarbyl group with a carbon number of 1 to 3; n and m represent the numbers of fluorine atoms binding to A.sup.3 and A.sup.4, with n+m=1 to 13 being satisfied), comprising reacting a chlorine-containing sulfide compound represented by the following formula (1):
(Cl).sub.n-A.sup.1-S-A.sup.2-(Cl).sub.m  (1)
(wherein A.sup.1 and A.sup.2 are independently an optionally substituted hydrocarbyl group with a carbon number of 1 to 3; n and m represent the numbers of chlorine atoms binding to A.sup.1 and A.sup.2, with n+m=1 to 13 being satisfied) and a fluorinating agent.

A method for preparing a dicyanoalkane may omit a filtration for a catalyst after a cyanation reaction can by carrying out the cyanation reaction in a state in which precipitation of a metal catalyst is suppressed. A method for preparing a dicyanoalkane may involve cyanating one or more aliphatic dicarboxylic acids and/or salt(s) thereof with an ammonia source in the presence of a predetermined compound and a catalyst, wherein, in the cyanation, the amount of the predetermined compound is maintained at a predetermined amount or more with respect to the catalyst.

There is provided a catalyst that enables the production of isobutylene with a high selectivity in the production of isobutylene by dehydration of isobutanol. The catalyst according to the present invention contains at least one metal selected from Group 6 to Group 14 metal elements in Period 4 to Period 6 of the periodic table, in alumina which includes alumina consisting of one or more crystal phases of a monoclinic crystal phase, a tetragonal crystal phase, and a cubic crystal phase.

Provided is a catalyst which comprises a compound represented by formula (1) and which exhibits activity for at least one type of reaction selected from among hydrosilylation reaction or hydrogenation reaction with respect to an aliphatic unsaturated bond and hydrosilane reduction reaction with respect to a carbon-oxygen unsaturated bond or a carbon-nitrogen unsaturated bond. Formula (1): M.sub.n(L.sub.m) {M represents Fe, Co, or Ni having an oxidation number of 0, L represents an isocyanide ligand represented by formula (2), n denotes an integer of 1-8, and m denotes an integer of 2-12. Formula (2): (CN).sub.x—R.sup.1 (R.sup.1 represents a mono- to trivalent-organic group having 1-30 carbon atoms, optionally being substituted by a halogen atom, and optionally having interposed therein one or more atoms selected from among O, N, S, and Si; and x denotes an integer of 1-3.)}.

The object of the present invention is to provide a method which provides a diaminobiphenyl compound in a high yield and in a short period of time by a benzidine rearrangement reaction of a hydrazobenzene having a bulky substituent group at the meta position. Specifically, the present invention provides a method for preparing a diaminobiphenyl compound represented by the following formula (1):

##STR00001##

wherein, X.sub.1 and X.sub.2 are, independently of each other, a group selected from the group consisting of a trifluoromethyl group and, optionally fluorinated, isopropyl, isobutyl, sec-butyl, tert-butyl and neopentyl groups, comprising a step of subjecting a diphenylhydrazine compound represented by the following formula (2)

##STR00002##

wherein X.sub.1 and X.sub.2 are as defined above,
to a benzidine rearrangement reaction in the presence of an organic solvent and an inorganic acid at a temperature of from −70° C. to −11° C.
to obtain the diaminobiphenyl compound represented by the formula (1).

An object is to prevent lowering in the yield of R—COF due to contamination by impurities and thereby to produce a high-purity product of R—COF in a stable manner. According to the present invention, provided are: a method of purifying a carboxylic acid fluoride, comprising a step of removing a hydrogen halide by bringing a carboxylic acid fluoride containing the hydrogen halide into contact with a metal fluoride; a method of producing a high-purity carboxylic acid fluoride, comprising a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride as well as a high-purity carboxylic acid fluoride obtained therefrom; and a method of using a metal fluoride as an adsorbent for a hydrogen halide in a method of removing a hydrogen halide from a carboxylic acid fluoride containing the hydrogen halide.

An object of the present invention is to provide a catalyst capable of improving the selectivity of unsaturated aldehydes and unsaturated carboxylic acids, and a catalyst containing molybdenum, antimony, bismuth, and iron, wherein an atom ratio of the antimony to the molybdenum on a surface of the catalyst is greater than an atom ratio of the antimony to the molybdenum in the entire catalyst is provided.

A method for producing a sugar fatty acid ester characterized in that a fatty acid ester and a saccharide are subject to a transesterification reaction using a weakly basic ion exchanger having a pK.sub.b of 3 to 7 as a catalyst.

A porous carbon material, wherein a half width (2θ) of a diffraction peak (10×) (38° to 49°) by X-ray diffraction is 4.2° or less, and wherein a ratio (mesopore volume/micropore volume) of a mesopore volume (cm.sup.3/g) measured by a BJH method to a micropore volume (cm.sup.3/g) measured by a HK method is 1.20 or more.