Abstract: A preparation process of N,N′-dialkylalkanediamine by reacting dihaloalkane with lower alkylamine characterized by carrying out the reaction with controlling the residual amount in the reaction system of haloalkaneamine intermediate represented by the formula (4): wherein R is a lower alkyl group, R1 and R2 are a hydrogen atom or a lower alkyl group, X is a chlorine, bromine or iodine atom, and n is an integer of 2 to 6, and the invention inhibits formation of by-products cyclic dialkyldiamine and trialkylalkanetriamine and can provide desired N,N′-dialkylalkanediamine with a high yield.

Abstract: An improved preparation process for an aromatic mononitro compound comprising reacting an aromatic compound with mixed acid consisting of nitric acid, sulfuric acid or phosphoric acid and water, wherein these flow to react with each other in a reactor comprising a tube inside of which more than one twisted tabular members are aligned in sequence in a manner that a front margin of a twisted tabular member is substantially perpendicular to an back margin of the preceding member, can resolve a number of problems such as an inadequate mixing efficiency, reduction of a reaction rate, associated voluminal increase/complication of a reactor and difficulty in securing safety as well as provide the aromatic mononitro compound with minimal amount of by-products in a considerably short period.

Abstract: A method for preparing an improved catalyst for use in the preparation of chlorine by the oxidization of hydrogen chloride with an oxygen-containing gas. The catalyst mainly comprises chromium oxide and can be used for a long period of time particularly under low oxygen content conditions, and the activity of the catalyst does not easily deteriorate, and in other words, the catalyst has a long life. Furthermore, there are disclosed the catalyst obtained by this preparation method, and a method for preparing chlorine from hydrogen chloride by the use of the catalyst. The method for preparing the improved catalyst comprises adding copper, an alkali metal and a rare earth metal, or adding chromium, copper, an alkali metal and a rare earth metal to a catalyst containing chromium oxide as a main component, and then calcining the catalyst at a temperature of 800.degree. C. or less.