SU702006A1 - Method of preparing 4-nitrodiphenylamine-2-carboxylic acid derivatives - Google Patents

Description

 .-1, The invention relates to an improved method for the preparation of 4-nitrodiphenylamine-2-carboxylic acid derivatives of the general formula IfJ ede X1-CH}; - oCHj), Bg-OCH3, which are potentially bio-synthetic. ki active substances - derivatives of acridine. The literature describes methods for the preparation of 4-nitrodiphene amine-2-carboxylic acid derivatives, one of which is concluded in that the mixture of 2-fluoro-5-nitrobenzoic acid and o-xylidine is heated, stirred in an oil bath at 140-150 C. For 4 hours ... After cooling, the reaction mixture is made alkaline with 10% NaOH and unreacted o-xylidine 1 is distilled off with steam. The second method is that 2-chloro-5-n-trobenzoic acid is reacted with arylimines According to the method of Ulman in amyl alcohol in the presence of potash and a catalyst of natural Neu-copper followed by distilling off the solvent and excess arylamine and purifying the product using activated charcoal 2. . The disadvantages of these methods are: in the first method, the use of a mechanical stirrer during condensation; the use of stripping. with steam to remove excess arylamine; in the second method, the use of such diluted solvents, such as amyl; steam distillation of an organic solvent and an excess of arylamine; the use of a catalyst of powdered copper, as well as a lack of a high yield of the target product. The aim of the invention is to eliminate these drawbacks - to simplify the process and increase the yield of the target product. Said Target is achieved in the manner described.

that 2-chloro-5-nitrobenoic acid is reacted with arylMin in the presence of potash in dimethylformamide, and the target product is isolated by acidification of the reaction mixture. The process is usually carried out at a temperature of 140-150 ° C.

The target product is isolated by acidifying the reaction mass with concentrated hydrochloric acid to pH 3 to convert the potassium salt of 4-nitrodiphenylamine-2-carboxylic acid to free acid, and also to reduce the excess of potash and unreacted aromatic amine, which is converted into hydrochloric salt water solution.

the difference of the described method is that the process is carried out in the presence of dimethylformamide and the desired product is isolated by acidification of the reaction mixture. The target product is completely acidified with a yield of 75-79% of theory.

Example 1. A mixture of 5 g (0.025 g-mol) of 2-chloro-5-nitrobenvoic acid, 10.7 g (0.1 g-ml) of p-toluidine, 5 g of anhydrous potash, 50 ml of dimethylformamide is heated in a round bottom flask fridge in a metal bath at 140-150 ° C for 3.5-4 hours. After heating, the reaction mixture is diluted with 500 ml of water and acidified at 60 ° C with pH 3 to 3. The precipitate is filtered off with heat, washed on hot water and dried. The yield is 5.06 (yellow fine-crystalline powder with a T ... PL. 25b-257 ° C, which corresponds to the literature data) of 4-methyl-4-nitrodiphenylamine-carboxylic acid.

Example 2. 4-methoxy-4-nitp6-diphenyl .min-2-carboxylic acid.

A mixture of 5 g (0.025 g-mol) of 2-chloro-5-nitrobenzoic acid, 12, .3 g (0.1 g-mol) of p-anisidine, 5 g of anhydrous potash, 50 ml of dimethylformamd is heated in a round bottom flask with fridge in a metal bath at 140-150 ° C for 3.5-4 hours. After heating, the reaction mixture is diluted with 500 ml of water 5 and at 60 ° C acidified with concentrated hydrochloric acid to pH 3. The precipitate is filtered off in the form of heat, washed on the filter hot water and dried. Yield 5.64 g Q (79%), a yellow crystalline powder with so pl. 230-23lc, which corresponds to literature data.

Claims (2)

1. Authors certificate of the USSR 331058, cl., C 07 S. 101/54, 1969. 2. Gaydukovich A.Ya., Shtuchna V.P., Levitin Y.Y. Synthesis of some 7-nitrOacridine transient. Pharmacy vol. 2. Kiev, ed. Yorovye 1975, p. 24-26.