DE90960C - - Google Patents

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CLASS 12: Chemical processes and apparatus.

Patented in the German Empire on July 12, 1896.

As is well known, the oxyazobenzene is almost completely reduced in acidic solution split into aniline and p-amidophenol. It is further, from the investigations of P. Jacobson and his students (Berl. Reports 25, p. 992; 26, p. 681, 688, 699; Annalen 287, p. 97) known that the alkyl ethers of oxyazobenzene with the same treatment in semidines (derivatives of o- or p-amidodiphenylamine) pass over.

It has now been found that the acid esters of oxyazobenzene behave significantly differently demonstrate. When reduced, they produce oxydiamidodiphenyl bases; z. B. will from the acetyl-oxyazobenzene one of the oxyhydrazobenzene isomers in considerable yield Base obtained, which from it by rearrangement and with splitting off of the acetyl groups arose and which according to their behavior as Oxydiamidodiphenyl

OH-C ₆ H ₃ NH ₂

C ₆ H ₄ NH,

must be grasped.

Example:

log acetyl-oxyazobenzene (see Wallach & Kiepenheuer, Ber. 14, p. 2617) will be fine ground and gradually in 60 ecm hydrochloric acid tin chloride solution with constant stirring (40 g tin chloride in 100 ecm 38 percent hydrochloric acid) registered. The liquid heats up here; by cooling with cold water care is taken that the temperature does not rise above 40 °. After standing for a day a large amount of a tin double salt has separated out from the reduction mixture, which essentially contains the oxydiamidodiphenyl in addition to some benzidine. This Tin double salt is sucked off sharply and strongly squeezed to prevent it from sticking Free hydrochloric acid. It is then dissolved in about 20 parts of water the tin is removed by means of hydrogen sulphide in the heat and the de-tinned solution evaporates in the Carbon dioxide flow strongly. By adding dilute sulfuric acid one now separates the benzidine as a sparingly soluble sulfate. After one has made sure that the Solution with sulfuric acid filtered from benzidine sulfate gives no more precipitation, neutralized they are first partially washed with caustic soda, then completely with concentrated soda solution. In this way the oxydiamidodiphenyl separates itself partly as white crystalline, partly as resinous precipitate. It can be generated by crystallization from water or benzene. be cleaned. Because of its ability to be oxidized, one must proceed quickly during the operations.

The Oxydiamidodiphenyl melts at 148 ^0, dissolves readily in alcohol, glacial acetic acid and hot water, and heavy in benzene. From hot water it crystallizes when it cools in coarse, tufted needles and goes back into solution with the addition of caustic soda. The alkaline solution turns dark brown on standing.

That the base is a primary diamine has been shown by examining its derivatives. It has been shown that a molecule of the base is formed with two aldehyde molecules

(2nd edition, issued on March 1st.)

Claims (1)

condenses and takes up two acetyl groups on acetylation with boiling glacial acetic acid. The salicylaldehyde derivative ,OH OH Η \ N = CHC ₆ H ₁ OH forms shiny golden, yellow-brown flakes with a melting point of 206 to 207 ⁰ . The p-nitrobenzaldehyde derivative C ^ HiN = CHCH ₁ NO ₁ , C _a H _a - , OH "-N = CHC ₆ H ₁ NO ₂ forms an orange-red flaky powder. Melting point 218 ⁰ . The diacetyl derivative OCH ₃ CtH, ,OH ³ ^ - -NHCOCH ₃ melts at 269 °. The position of the substituents in this oxydiamidodiphenyl is likely due to following formula NH OH reproduced. . In any case, the base must be a rearrangement product of the p-oxyhydrazobenzene NH-NH- OH- in a benzene nucleus contain the amide and hydroxyl groups in the para position to each other. The oxydiamidodiphenyl can be used to represent dyes, as well as photographic Developers can be used with advantage. Instead of the acetyl-oxyazobenzene directly through Reduction in mineral acid solution can be converted into oxydiamidodiphenyl also first the acetyloxyhydrazobenzene (Goldschmidt & Brubacher: Reports 24, p. 2309) from it and the latter through Convert the rearrangement to oxydiamidodiphenyl by means of acids. The acyl derivatives behave analogously to acetyl-oxyazobenzene and acetyl-oxyhydrazobenzene other p-oxyazo compounds which are not in the one para position to the azo group are substituted, as well as the corresponding hydrazo compounds. The reaction proceeds in a different sense if one of doubly para-substituted azo bodies, such as B. the acetylated product from diazotized p-toluidine and phenol. Goldschmidt & Brubacher have made experiments in this direction (see Reports 24, p. 2311), but their statements could not be confirmed, rather the two semidines were obtained in the normal way during the reduction: the o-semidine with a melting point of 136 °, characterized by the formation of a Azimids melting point of i88 ° nitrous upon exposure to acid, and the p-semidine of melting point 118-119 ^0, which proved to be identical with that of R verifiable old (Annalen 255, pages 166-167) already shown p -Amidophenyl-p-tolylamine. Pateντ-Αν saying: Process for the preparation of oxydiamidodiphenyl bases by acidic reduction of the acyl compounds of p-oxyazobenzene and other p-oxyazo compounds, which in one Para position to the azo group are not substituted, or by rearrangement of the corresponding Hydrazo compounds by means of acids.