DE347375C - Process for the preparation of nitro-3-quinolines - Google Patents

Description

Process for the preparation of nitro-3-quinolines. Through .the main pategt is a process for the preparation of nitro 3-quinoline and its derivatives protected, consisting in the fact that one o-amidated, aromatic aldehydes or retones or derivatives of these aldehydes and ketones with methazonic acid N O H: C H - C H: N 0 O H condenses.

It has now been found that derivatives of nitro-3-quinoline can also be obtained if the men from o-aminoarylcarboxylic acids or their derivatives with methazonic acid available ß-Nitroäthyfidenarylamino-o-carboxylic acids or their derivatives with suitable Condensing agents, e.g. B. acetic anhydride and anhydrous sodium acetate. Example i.

A solution of 27.4 parts of anthranilic acid in 500 parts of water and 50 parts of 15 percent hydrochloric acid is mixed with a solution of methazonic acid prepared from 24.5 parts of nitromethane according to Berliner Reports 40 [19o71 p. 3441]. After a short time, the 2 - ß-Nitroäthylidenaminobenzol-l-carboxylic acid separates out in yellow needles, which melt after crystallization from alcohol between 196 and 1970.

The solution of 20.8 parts of 2 - ß-Nitroäthylidenarninobenzol = i-carboxylic acid in 100 parts of acetic anhydride is slowly poured into a boiling mixture of 5o Parts of anhydrous sodium acetate and 100 parts of acetic anhydride entered. When the vigorous reaction has ended, the mixture becomes weak for an hour Received boiling, then the acetic anhydride was distilled off in vacuo and the residue added about .iooo parts of hot water. When cooling, the formed separates Nitro-3-oxy-q.-quinoline. By crystallization from nitrobenzene or formic acid it is obtained in pale brown crystals which melt at over 300 ° and provide amino-3-oxy 4-quinoline in the reduction, its acetyl compound Melts 289 °.

Instead of anthranilic acid, its derivatives or other o-aminoarylcarboxylic acids can be used or use their derivatives. Example e. 2i, 7 parts of 5-bromo-2-aminobenzene-i-carboxylic acid are dissolved in 500 parts of water and 10 parts of hydrochloric acid. To the filtered solution becomes a methazonic acid solution weakly acidified with hydrochloric acid, prepared from "i2,3 Parts of nitromethane are added. After a few moments a yellow precipitate will appear of 2 # ß-nitroethylideneamino-5-bromobenzene-i-carboxylic acid; which sucked off after 12 hours will.

The body is very sparingly soluble in water. Recrystallized from hot alcohol it melts at 182 ° with decomposition; it is special against alkalis and acids inconsistent in heat.

2o parts 2. "Q-Nitroäthylidenamino-5-brorro, -benzene-i-carboxylic acid are boiled with 150 parts of acetic anhydride and 15 parts of anhydrous sodium acetate for 1/4 hour; after cooling, it is diluted with plenty of water, the precipitate is suctioned off and dried at 100 ° Resulting from the escape of water: -nitro-3-oxy-q.-bromo-6-quinoline It is almost insoluble in most solvents, even in the heat, from nitrobenzene it is obtained in light brown flakes which do not yet melt at 300 °. It dissolves very easily in caustic alkalis and less easily in carbonic acid alkalis. Hydrochloric acid or sulfuric acid removes the body from these solutions unchanged. Example 3. 58 parts of concentrated hydrochloric acid are poured over 18.7 parts of 2-aminonaphthalene-3-carboxylic acid and then dissolved in 50 ° parts of water while hot. After cooling to 60 ", methazonic acid acidified with hydrochloric acid, prepared from 12.3 parts of nitromethane, is added Hours of suction and drying at 100 °. Recrystallized from alcohol, it melts with decomposition at 220 °.

18 parts of the ß-nitroethylideneamino compound are gently boiled for 6 hours with 45 parts of anhydrous sodium acetate and i5o parts of acetic anhydride and, after cooling, 300 parts of cold water are added. The precipitate is filtered off with suction, washed carefully and dried at 100 °. The 3-nitro-4-oxy-a-anthrapyridine formed is obtained by recrystallization from nitrobenzene received pure.

It has not yet melted at 300 ° and is in the ordinary organic Almost insoluble in solvents, somewhat soluble in nitrobenzene and also in concentrated form Formic acid. It dissolves easily in caustic, more difficultly in carbonic alkalis; it is separated from these solutions unchanged by mineral acids.

Claims (1)

PATENT CLAIM: Modification of the process protected by patent 335197 for the preparation of nitro-3-quinolines, consisting in the fact that one consists of o-aminoarylcarboxylic acids or their derivatives with methazonic acid obtainable ß-Nitroäthylidenarylamino-ocarbonsäuren or their derivatives treated with condensing agents.