Abstract: The invention relates to a process for the preparation of nitroanilines by the reaction of chloronitrobenzenes with ammonia at elevated temperature and under elevated pressure, and in the presence of chlorinated aromatic hydrocarbons.Nitroanilines are important precursors and intermediate products for the preparation of dyestuffs, pharmaceuticals and plant protection agents.

Abstract: The invention relates to an apparatus for differential thermal analysis, consisting of a furnace with holders to receive vessels sealed on all sides for samples and reference substances and with temperature sensors, which are in good thermal contact with the vessels, characterized in that the holders consist of a metal cylinder open on one side, whose inner diameter is adjusted to the outer diameter of the vessels, and whose bottom is in good thermal contact via a base plate with the furnace, and sensors arranged on the base plate in the immediate vicinity of the cylinder bottom.

Abstract: A method for differential thermal analysis and a furnace which is suitable for analytical measurements is heated by radiation. For this purpose, a radiation source whose radiation is absorbed by the furnace wall is arranged near to the furnace. The furnace is preferably formed as a hollow cylinder which surrounds the radiation source. An incandescent coil may, for example, be used as the radiation source.

Abstract: A furnace which is suitable for analytical measurements is heated by radiation. For this purpose, a radiation source whose radiation is absorbed by the furnace wall is arranged near to the furnace. The furnace is preferably formed as a hollow cylinder which surrounds the radiation source. An incandescent coil may, for example be used as the radiation source.

Abstract: In a method of differential thermal analysis (DTA), an original sample is divided into at least two part samples and one or more part samples are tempered at temperatures below the lowest temperature occurring during DTA at the beginning of decomposition. The differential thermal analysis is then carried out on tempered and untempered samples and the DTA curves are compared with each other.

Abstract: A furnace which is suitable for carrying out differential thermal analysis of long duration comprises two symmetrical halves having equal heat capacities. Equal sized bores are provided in both halves for a sample container. There are additional bores in the lower half for differential thermoelements. The two halves of the furnace are advantageously provided with filament windings of equal electrical resistance.