Patent GB-303389-A (GB)
Title: The manufacture of new carboxylic acids of the fatty-aromatic series
IPC: C07C57/60
Filed: 1927-07-01
Abstract: 303,389. Carpmael, A., (I. G, Farbenindustrie Akt.-Ges.). July 1, 1927. Samples furnished. Carboxylic acids.-New carboxylic acids are obtained by heating an unsaturated acid of the type (wherein X represents hydrogen, halogen, alkyl, aryl, carboxyl, or other monovalent substituent), or a hydrogen halide addition product of such an acid, with a polycyclic aromatic hydrocarbon containing more than two condensed benzene nuclei, or with a substitution product thereof. such as a halogen, alkyl, hydroxy, or alkoxy derivative. The reaction may be effected in presence of an acid condensing agent and/or of a diluent. The products are applicable as intermediates for the manufacture of dyestuffs and pharmaceutical substances. The following examples are specified :-(1) anthracene is heated for some hours with acrylic acid at 110-170‹ C. while passing a current of hydrochloric acid gas through the mixture, and the precipitate obtained on pouring the cooled mass into water is dissolved in caustic alkali solution and reprecipitated by acidifying the solution; (2) the same product is obtained by boiling a solution of anthracene and a- or #-chloropropionic acid in dichlorbenzene, removing the dichlorobenzene by steam distillation, dissolving the product in caustic alkali solution, and acidifying as in (1); (3) an anhydride, probably of the constitution is obtained by heating anthracene with maleic acid or maleic anhydride to 170‹ C., pouring into water, dissolving the separated precipitate in caustic soda solution, crystallizing the sodium salt, and acidifying and boiling its aqueous solution; a similar product is obtained when the anthracene is replaced by 9 10-dichloranthracene; (4) anthracene is heated with cinnamic acid to 170‹ C. while passing a current of hydrochloric acid gas through the mixture, and the product obtained by dissolving and precipitating as in (1) is freed from unchanged cinnamic acid, e.g. by extracting the latter with acetic acid: similar products are obtained when the cinnamic acid is replaced by its substitution products such as o- or p-chloro-#-phenylacrylic acids or ohydroxy-#-phenylacrylic acids; (5) 9 : 10-dichloranthracene or other substitution product of anthracene, such as 1 : 5-dichloranthracene, 2 : 7- dimethylanthracene, or 1-hydroxyanthracene is heated for 3 hours with chloropropionic acid to about 180‹ C., and the product which separates on pouring into water is dissolved and precipitated as in 1(); (6) similar products are obtainable from phenanthrene and retene by heating with chloropropionic acid. Chrysene is also specified as a suitable hydrocarbon, and the following are also specified as suitable acids :- crotonic acid, alpha-chloroacrylic acid, #-chlorocrotonic acid, alpha-chloro-#-phenylacrylic acid, and chlorosuccinnic acid. The halogenides, esters, or anhydrides may be employed in place of the acids themselves. Specifications 273,321, 274,095, and 286,685 are referred to. Azo dyes.-The product obtained as above from 1-hydroxyanthracene and #-chloropropionic acid couples with diazo compounds, e.g. yields an orange-yellow product with diazotized p-nitraniline.