Abstract: There are provided a dihalogen derivative represented by formula (2): wherein X represents a halogen atom and R2 represents a protective group for a hydroxyl group; a process for producing the same; and a process for producing vitamin A by use of said dihalogen derivative.

Abstract: A tetraene derivative of the formula (1): ##STR1## wherein Ar represents an aryl group which may be optionally substituted with at least one substituent, and R.sup.1 and R.sup.2 are identical or different and represent a hydrogen atom, a lower alkyl group or a protective group of a hydroxyl group; synthesis methods therefor and synthesis methods using the same.

Abstract: A process for producing 1-bromo-4-phenylbutane of the formula (1): ##STR1## which is characterized by the steps of; reacting 4-bromobutyryl halide of the formula (2): ##STR2## where X is a halogen atom, with benzene in the presence of a Lewis acid to give a 4-bromobutyrophenone of the formula (3): ##STR3## and reacting 4-bromobutyrophenone compound of the formula (3) with hydrogen in the presence of a metal catalyst.

Abstract: The present invention concerns a process for producing crystals of 3-amino-2-hydroxyacetophenone salt having a high bulk density and improved flow properties, by treating 3-amino-2-hydroxyacetophenone of formula (1) ##STR1## or hydrogen halide salt thereof with sulfuric acid, in a solvent.

Abstract: 3-?4-(4-Phenyl-1-butoxy)benzoyl!amino-2-hydroxyacetophenone is prepared by reacting a benzoate ester with a halobutylbenzene in the presence of a basic compound and an aprotic polar compound in an aromatic hydrocarbon solvent to obtain a corresponding ether, alkali hydrolyzing the ether in an aromatic hydrocarbon solvent and precipitating a hydrolysate with an acid to obtain 4-(4-phenyl-1-butoxy)benzoic acid, reacting a halogenating agent with this benzoic acid derivative in an aromatic hydrocarbon solvent to obtain an acid halide, and reacting the acid halide in an aromatic hydrocarbon solvent with a corresponding aromatic amine.

Abstract: A process is disclosed for producing an amine by carrying out a reductive amination of a cyclic ketone or by carrying out a reduction of an imino derivative of a cyclic ketone to the corresponding amine which process is characterized in using a cobalt catalyst containing a carbonate of an alkaline earth metal and/or lanthanum oxide.

Abstract: Amines are produced in high yield by the process which comprises allowing a cyclic ketone to react with ammonia in the presence of active carbon to produce imino derivatives and then, allowing the imino derivatives to react with hydrogen in the presence of a hydrogenating catalyst.