Novel thioxanthene derivatives and salts thereof and a process for the manufacture of same

摘要

The invention comprises 9-thioxanthenols substituted also in the 9-position by a tertiary aminoalkyl group in which the alkyl moiety contains from 3 to 7 carbon atoms and in which the tertiary amino group is either a dialkylamino group in which the alkyl groups each contain up to 4 carbon atoms or a nitrogen containing 5- or 6-membered heterocyclic ring which may contain oxygen, sulphur or nitrogen as an additional hetero atom, and substituted in one or more of positions 1 to 8 by one or more acyl groups; and acid-addition salts and quaternary ammonium compounds thereof; and their preparation by condensing an acylated thioxanthone in which the acyl group is protected, e.g. by ketalization, with an organometallic derivative of the appropriate tertiary amino-alkyl group, hydrolysing the metal-containing condensation product so obtained and splitting off the protective group. Organometallic compounds referred to are those of lithium, magnesium and zinc, and the use of Grignard reagents is preferred. The hydrolysis is desirably effected with aqueous ammonium chloride. The preparation of 2-acetyl-9-hydroxy - 9 - (o - dimethylamino - propyl) - thio - xanthene is described, and a list of salt-forming organic and inorganic acids and quaternizing agents is provided. 2 - Acetyl - thioxanthone monoketal is prepared by condensing p-iodo-acetophenone with thio-salicylic acid to give 4-acetyl-phenyl 2-carboxyphenyl sulphide, heating this in syrupy polyphosphoric acid to effect ring closure and give 2-acetyl-thioxanthone, and ketalizing this with ethylene glycol.