2,5-Diaminophenol inorganic salts prodn. - by catalytically hydrogenating 2-amino-5-nitro-phenol in anhydrous medium and pptg. with inorganic acid

摘要

Addn. salts of 2,5-diaminophenol (I) with inorg. acids are prepd. in high yields and purity by (a) treating 2-amino-5-nitrophenol with hydrogen in the presence of a metallic hydrogenation catalyst (pref. Raney- or Ruppe-nickel) in anhydrous or almost anhydrous conditions, (b) freeing the reaction mixt. from catalyst, (c) treating with an inorg. acid (pref. concd. sulphuric acid) and (d) isolating the resulting acid addn. salt of (I). (I) is useful as an inter, e.g. for oxazoles, oxazines and other heterocyclic cpds., as well as for 5-hydroxy-4,7-phenanthroline cpds. which are pharmacologically active (esp. as central stimulants).