Abstract: A process is provided for the production of 2,7-dibromofluorenone. According to the process, a 2,7-dibromofluorene-contianing raw material is oxidized with molecular oxygen in the presence of a phase transfer catalyst such as a quaternary ammonium salt in a heterogeneous, mixed solvent of an aqueous solution of a caustic alkali and a water-insoluble organic solvent. Crude crystals of 2,7-dibromofluorenone, which have been obtained by the oxidization, can be purified by recrystallization to recover 2,7-dibromofluorenone as crystals having a purity of at least 99 wt. %.

Abstract: A method for preparing bromofluorenes includes a step of dispersing a compound selected from the group consisting of fluorene, fluorenone, and derivatives of fluorene and fluorenone in water to prepare a disperse system. Bromination is initiated by adding bromine Br2 into the disperse system. Thus, bromofluorenes can be efficiently and economically prepared without using any environmentally harmful organic solvent requiring a high cost to dispose of.

Abstract: A process is provided for the production of 2,7-dibromofluorenone. According to the process, a 2,7-dibromofluorene-contianing raw material is oxidized with molecular oxygen in the presence of a phase transfer catalyst such as a quaternary ammonium salt in a heterogeneous, mixed solvent of an aqueous solution of a caustic alkali and a water-insoluble organic solvent. Crude crystals of 2,7-dibromofluorenone, which have been obtained by the oxidization, can be purified by recrystallization to recover 2,7-dibromofluorenone as crystals having a purity of at least 99 wt. %.

Abstract: A method for preparing bromofluorenes includes a step of dispersing a compound selected from the group consisting of fluorene, fluorenone, and derivatives of fluorene and fluorenone in water to prepare a disperse system. Bromination is initiated by adding bromine Br2 into the disperse system. Thus, bromofluorenes can be efficiently and economically prepared without using any environmentally harmful organic solvent requiring a high cost to dispose of.

Abstract: At least one xylenol isomer can be separated and purified from a mixture, which contains the specific xylenol isomer and at least one organic substance other than the specific xylenol isomer, by bringing the mixture into contact with 1,1-di(4-hydroxyphenyl)cyclohexane as a host compound to form a complex of the specific xylenol isomer as a guest compound with the host compound and then having the specific xylenol isomer released from the complex. The mixture may contain at least two xylenol isomers consisting of 2,4-xylenol and 2,5-xylenol, and at least one of the xylenol isomers can be separated and purified by having it released from its complex with the host compound.

Abstract: A method of manufacturing aromatic urethanes utilizes a urea production process wherein a primary aromatic amine, an aromatic nitro-compound and carbon monoxide are made to react together in the presence of a catalyst and solvents, to produce N,N'-disubstituted urea, the solvlent used in the urea production process consisting at least partly of an amide or oxygen-containing sulfur compound, and having the functions of stabilizing the catalyst and preventing it from separating out in a solution, and of increasing the activity of the catalyst, the quantity of the solvent being sufficient to permit it to fulfill these functions effectively. The method additionally includes an aromatic urethane production process wherein the N,N'-disubstituted urea produced is made to react with an organic compound containing hydroxyl groups, to produce a primary aromatic amine and aromatic urethane, the primary aromatic amine being separated to obtain the aromatic urethane.