Abstract: Carboxylate (1) of the formula R.sup.1 COOR.sup.2 (where each of R.sup.1 and R.sup.2 independently represents an alkyl group, an alicyclic hydrocarbon group or an aryl alkyl group), an aromatic hydroxy compound of the formula R.sup.3 OH (where R.sup.3 represents an aromatic group with or without a substituent), and a catalyst are supplied to a batch reactor 1, and a transesterification between the carboxylate (1) and the aromatic hydroxy compound is performed to produce carboxylate (3) of the formula R.sup.1 COOR.sup.3 (where R.sup.1 and R.sup.3 are as defined above). After distilling off the by-produced alcohol and unreacted compounds using a distillation column 2, carbonate ester (4) of the formula R.sup.4 O--COOR.sup.5 (where each of R.sup.4 and R.sup.5 independently represents an alkyl group, an alicyclic hydrocarbon group or an aryl alkyl group) is supplied to the batch reactor 1.

Abstract: A industrially advantageous process for preparing dialkyl carbonates is provided. The process is characterized in that an alkylene carbonate and an alcohol are subjected to an transesterification in the presence of a catalyst which contains, as the catalytically active component, at least one rare-earth oxide. According to this process, the transesterification progresses rapidly due to the excellent activity of the catalyst, and the catalyst can be readily separated after termination of the reaction, allowing high efficiency isolation and purification of dialkyl carbonate.

Abstract: A method of producing ethylenediamines represented by the general formula ##STR1## wherein R represents a hydrogen atom, or a methyl or ethyl group, which comprises reacting an aziridine compound of the general formula ##STR2## wherein R is as defined, with ammonia in the gaseous phase in the presence of a solid acid catalyst. In another aspect, a method of producing ethylenediamines of the general formula (I), which comprises reacting a reaction product containing an aziridine compound of the general formula (II), obtained by the gaseous phase intramolecular dehydration reaction of an alkanolamine represented by the general formula ##STR3## wherein X represents the OH group or the NH.sub.2 group, Y represents the NH.sub.2 group when X is the OH group and the OH group when X is the NH.sub.2 group, and R is as defined,in the presence of a catalyst A, with ammonia in the gaseous phase in the presence of a solid acid catalyst (catalyst B).

Abstract: A method of producing ethylenediamines represented by the general formula ##STR1## wherein R represents a hydrogen atom, or a methyl or ethyl group, which comprises reacting an aziridine compound of the general formula ##STR2## wherein R is as defined, with ammonia in the gaseous phase in the presence of a solid acid catalyst. In another aspect, a method of producing ethylenediamines f the general formula (I), which comprises reacting a reaction product containing an aziridine compound of the general formula (II), obtained by the gaseous phase intramolecular dehydration reaction of an alkanolamine represented by the general formula ##STR3## wherein X represents the OH group or the NH.sub.2 group, Y represents the NH.sub.2 group when X is the OH group and the OH group when X is the NH.sub.2 group, and R is as defined, in the presence of a catalyst A, with ammonia in the gaseous phase in the presence of a solid acid catalyst (catalyst B).

Abstract: A method for regeneration of catalyst which comprises phosphorus and alkali metal element and/or alkaline earth metal element and was deteriorated by use to produce aziridine compound represented by the general formula ##STR1## wherein R is hydrogen, a methyl group or an ethyl group, by a catalytic vapor-phase intramolecular dehydration reaction of alkanolamine represented by the general formula ##STR2## wherein R is as defined in the formula (II), X is OH or NH.sub.2, and Y is either NH.sub.2 when X is OH or OH when X is NH.sub.2, characterized in that the deteriorated catalyst is contacted with gaseous volatile phosphorus compound.

Abstract: A process for producing an aziridine compound represented by the following general formula ##STR1## wherein R represents hydrogen, or a methyl or ethyl group, which comprises intramolecularly dehydrating an alkanolamine represented by the following formula ##STR2## wherein R is as defined, X is OH or NH.sub.2, and Y is NH.sub.2 when X is OH, and OH when X is NH.sub.

Abstract: A catalyst for production of methacrylic acid, said catalyst being molded in a ring-like shape having an outside diameter of 3.0 to 10.0 mm, an inside diameter 0.1 to 0.7 times the outside diameter and a length 0.5 to 2.0 times the outside diameter, said catalyst comprising a catalytically active material having the composition represented by the following general formulaMo.sub.a P.sub.b A.sub.c B.sub.d C.sub.e D.sub.f O.sub.