METHOD FOR SYNTHESIS OF 2,1-DIAZONAPHTHALINONE-CHLORIDE-5-SULPHONIC ACID Russian patent published in 2011 - IPC C07C309/35 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for synthesis of 2,1-diazonapthalinone-chloride-5-sulphonic acid, which involves synthesis in four steps. At the first step, an initial reagent in form of a sodium salt of 1-naphthol-5-sulphonic acid reacts with sodium nitrite in a hydrochloric acid medium. At the second step, the obtained 2-nitroso-1-naphthol-5-sulphonic acid is added to a sodium hydrosulphite (dithionite) solution, where temperature of the reaction mixture during addition is kept not higher than 50°C, and kept in the range of 80-100°C after addition. Said temperature is maintained for 5-30 minutes. The third step involves diazotation of 2-amino-1-naphthol-5-sulphonic acid. At the fourth step, extraction of 2,1-diazonaphthalinone-chloride-5-sulphonic acid is carried out on a mixture of ice and water at temperature 0-5°C, where the ice is taken in amount of not more than a quarter of the total weight of the water-ice mixture.

EFFECT: high output and degree of purity of the product, method can be used in making the photosensitive component of a heat resistant positive photoresist.

1 cl, 3 ex