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.

Abstract: A process is disclosed which prepares a cinnamic acid from a cinnamate ester by starting the hydrolysis reaction of the cinnamate ester with an alkali by use of water as a solvent in a heterogeneous binary-phase liquid system to obtain an aqueous alkaline solution of an alkali cinnamate and precipitating the cinnamic acid by conducting an acidifying reaction of said aqueous alkaline solution with a mineral acid so as to keep a pH value of not more than 4 in a resulting liquid.

Abstract: A polymethylene polyphenyl polyisocyanate composition comprising polymethylene polyphenyl polyisocyanates, a part of the isocyanate groups contained therein being substituted by a carbamate group, or said polymethylene polyphenyl polyisocyanates having the substituted carbamate group and polymethylene polyphenyl polyisocyanate not having carbamate group. The total amount of the carbamate groups contained in the composition is up to 10 percent by mole based on the total amount of isocyanate groups contained in the composition. The composition is useful for the preparation of rigid polyurethane which has many industrial applications. A process for the preparation of the composition is also disclosed.

Abstract: It is disclosed that, in the process for producing polymethylene polyphenyl polycarbamates through the reaction of N-phenyl carbamate with formaldehyde or a formaldehyde-supplying substance in the presence of an acid catalyst, if the reaction is carried out in the concurrent presence of at least one compound or a mixture of at least two compounds selected from the group consisting of N-carboalkoxy (or cycloalkoxy)-2-oxa-4-aza-naphthalenes, bis(N-carboalkoxy(or cycloalkoxy)-anilino)-methanes and N,N'-dicarboalkoxy (or cycloalkoxy)aminobenzyl-anilines, the object product, polymethylene polyphenyl polycarbamate, can be obtained at a high yield.

Abstract: Aromatic urethanes can be produced by interacting an aromatic primary amino compound having a nitro group, a nitroso group or a carbamate group, an organic compound having at least one hydroxyl group, and carbon monoxide in the presence of a catalytic system composed of a platinum group metal and/or a compound thereof serving as catalyst and a Lewis acid and/or a compound thereof as promoter under high temperature and high pressure conditions. For instance, the interaction of 2-amino-4-nitrotoluene, ethanol and carbon monoxide in the presence of palladium chloride and a ferrous chloride-pyridine complex under high temperature and high pressure conditions can yield 2,4-diethylcarbamatetoluene.

Abstract: In a process for preparing an aromatic urethane which comprises reacting an aromatic nitro compound, an organic compound containing at least one hydroxyl group, and carbon monoxide at elevated temperature and pressure in the presence of a catalytic system composed of a catalyst consisting of a platinum metal, a platinum metal compound, and/or a platinum metal compound-containing compound and a promoter consisting of a Lewis acid and/or a Lewis acid-containing compound, an organic primary amino compound, a urea compound, a biuret compound, an allophanate compound, or a mixture thereof is added to the reaction system whereby the reaction rate is increased and the yield of the desired product is enhanced. For example, 2,4-diethylcarbamatetoluene can be prepared in quantitatively high yield by reacting 2,4-dinitrotoluene, ethanol, carbon monoxide, and a small amount of aminonitrotoluene at elevated temperature and pressure in the presence of palladium chloride and ferrous chloride-pyridine complex.

Abstract: Aromatic urethanes are produced by interacting an aromatic nitro compound, an organic compound containing hydroxyl groups and carbon monoxide in the presence of a catalyst composed of elemental selenium or a selenium compound and of a promoter composed of a bicyclic amidine together with a phenolic compound or a carboxylic acid. The interaction proceeds smoothly with the aid of a small amount of the promoter, attended with secondary production of amino compounds only in small amounts. For instance, 2,4-diethyldicarbamatetoluene is obtained at a yield of 87% by interacting 2,4-dinitrotoluene, ethanol and carbon monoxide in the presence of a catalytic system composed of metallic selenium, 1,8-diazabicyclo(5,4,0)-undecene-7 and acetic acid.

Abstract: An aromatic urethane of high quality and excellent heat stability can be produced in high yield by reacting an aromatic nitro compound, a hydroxyl group-containing organic compound and carbon monoxide in the presence of a catalytic system composed of (1) palladium, ruthenium, rhodium or a compound thereof, (2) a Lewis acid, and (3) ammonia. The use of such catalytic system can suppress undesirable side reactions to a satisfactory extent and ensures the reaction to proceed without causing any corrosion of a stainless steel reactor. If necessary, water may be added to the reaction system to increase the reaction velocity, by which the unit cost of the catalyst can be reduced.

Abstract: Aromatic urethanes can be produced in exceedingly improved yield when an aromatic nitro compound, an organic compound containing hydroxyl groups, and carbon monoxide are reacted in the presence of a catalyst composed of metallic (elemental) selenium or a selenium compound and a base serving as promoter, to which reaction system an aromatic amino compound and/or an aromatic urea compound which will be secondarily produced by the reaction has been previously added in order to suppress side reactions. For instance, when nitrobenzene, methanol and carbon monoxide are interacted in the presence of metallic selenium and triethylenediamine, the conversion of nitrobenzene is 68% and the percentage of formed methyl N-phenylcarbamate to the interacted nitrobenzene is 80%, whereas when the reaction is effected under the same reaction conditions indicated above with addition to the reaction system of aniline in an amount of about 15 wt.

Abstract: A method for the preparation of a halogenated aromatic amine, wherein a halogenated aromatic nitro compound is hydrogenated in liquid phase in the presence of a platinum-base catalyst to obtain a corresponding halogenated aromatic amine, the hydrogenation being carried out in the presence of an alkylmonoamine, an alicyclic amine or a polyalkylenepolyamine. The presence of the amine well suppresses a dehalogenation reaction which would otherwise be involved, so that not only a high purity halogenated aromatic amine is obtained, but also corrosion of a reactor is prevented.

Abstract: A process for preparing 1-aminoanthraquinone having high purity, which comprises either1. hydrogenating 1-nitroanthraquinone in an aqueous medium in the presence of a base using a hydrogenating catalyst, and then oxidizing the hydrogenation product, or2. hydrogenating crude 1-nitroanthraquinone containing dinitroanthraquinones as impurities or crude 1-aminoanthraquinone containing diaminoanthraquinones as impurities in an aqueous medium in the presence of a base using a hydrogenating catalyst, stopping the hydrogenation at a time when the 1-nitroanthraquinone or 1-aminoanthraquinone has been substantially reduced to 1-aminoanthrahydroquinone but the dinitroanthraquinones or diaminoanthraquinones remain substantially unreduced to diaminoanthrahydroquinones, removing water-insoluble materials from the reaction mixture, and then oxidizing the remaining water-soluble residue.

Abstract: A process for preparing aminoanthraquinones of high purity, which comprises catalytically hydrogenating nitroanthraquinones in the suspended state in an aqueous medium in the presence of a hydrogenating catalyst. In a preferred embodiment, the catalytic hydrogenation may be carried out in the presence of an organic or inorganic base, followed, if desired, by oxidizing the hydrogenation product.