Hoechst Aktiengesellschaft

Hartmut Heise

Manfred Hintzmann

Ernst Hille

Kurt Kummerle

Bernhard Mees

Rudiger Berthold

Wilfried Sahm

Reinhard Wagner

Eberhard Ritter

Lothar Schmitt

Bernd Leibmann

Dieter Morler

Max Schneider

Dieter Heck

A process for the preparation of 4-acylamino-2-aminoalkoxybenzenes of the general formula (1) ##STR1## in which R denotes an alkyl-C.sub.1 -C.sub.6 - or alkoxy-C.sub.1 -C.sub.4 -alkylene-C.sub.1 -C.sub.4 group and R' denotes a methyl or ethyl group, by pumping a solution or suspension of a 2,4-dinitroalkoxybenzene of the general formula (2) ##STR2## in which R has the abovementioned meaning, in a butyl acetate into a stirred suspension of a nickel catalyst on a kieselguhr carrier in butyl acetate, which has been initially introduced into an autoclave, at a hydrogen pressure of about 5 to about 50 bar, and a temperature of about 60.degree. to about 120.degree. C., at a rate which corresponds to the rate of hydrogenation of 2,4-dinitroalkoxybenzene to 2,4-diaminoalkoxybenzene, dehydrating the reduction solution by azeotropic distillation, after the hydrogenation, and acylating the resulting 2,4-diaminoalkoxybenzene with about 0.90 to 0.99 mole of the anhydride of an alkylmonocarboxylic acid having 2 to 3 carbon atoms, relative to 1 mole of 2,4-diaminoalkoxybenzene, at about -5.degree. to about +15.degree. C.

Process for the preparation of 4-acylamino-2-aminoalkoxybenzenes

A process for the preparation of o-nitrophenetole by allowing about 1.05 to about 1.4 mole of ethanol to act on 1 mole of o-nitrochlorobenzene in the presence of a phase-transfer catalyst in approximately 40 to approximately 70 percent by weight alkali metal hydroxide solution at temperatures from about 50.degree. to about 80.degree. C. in such a way that the ethanol concentration in the reaction mixture does not exceed 1.5 percent by weight throughout the course of the reaction.

Process for the preparation of o-nitrophenetole

A process for the preparation of 2,4-dinitrophenyl ethers of the general formula (1) ##STR1## in which R denotes an alkyl(C.sub.1 -C.sub.6) or alkoxy(C.sub.1 -C.sub.4)alky(C.sub.1 -C.sub.4) group by reacting 1 mole of 2,4-dinitrochlorobenzene in the anhydrous alcohol which is required for the ether formation and is of the general formula (2)

Process for the preparation of 2,4-dinitrophenyl ethers

Benzimidazolone-(2) is obtained in good yield and high purity when o-phenylene diamine is condensed with urea in water at a pH of 4 to 9 and a temperature above 90.degree. C.

Process for the preparation of benzimidazolone-(2)

3-Nitro-4-acetamino-toluene is obtained by introducing continuously a solution of 4-acetamino-toluene in sulfuric acid and, thereafter, aqueous 40 to 65% (by weight) nitric acid into the circulating reaction mixture. This process is advantageously performed in a device consisting of a closed circuit reactor, two inlets arranged successively in the direction of the product stream, a cooler and an outlet.

Process for the continuous manufacture of 3-nitro-4-acetylamino-toluene

The known condensation reaction of lower alkanoylacetic acid lower alkyl esters with aldehydes catalyzed by amines proceeds safe and in high yields if the amineis an aliphatic tertiary amine. The products are precursors of aromatic amines.

Process for the preparation of condensation products of acetoacetic

When continuously reacting an aqueous solution of 5-aminobenzimidazolone-(2) or a salt thereof with diketene then 5-acetoacetylamino-benzimidazolone is obtained in a smooth and safe reaction without foaming. The product results in high space-time yield and excellent quality.

Process for the manufacture of 5-acetoacetylamino-benzimidazolone

The liquid-phase catalytic hydrogenation of N-acetoacetyl arylamides to yield 3-hydroxybutyric acid arylamides proceeds much faster when amines, phosphines or trialkylphosphates are added. Thus, even with lower hydrogen pressures and at lower temperatures with a lower catalyst concentration, shorter reaction times are sufficient.

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Bad Soden am Taunus, Germany

Hartmut Heise