Amino-Substituted 2-Cumaryl-(3)-Chromenylium Salts

The invention relates to a process for the preparation of amino-substituted 2-cumaryl-(3')-chromenylium salts. Compounds of this kind are important as dyestuffs, especially in copying processes and, in electrophotography.

According to the state of the art, a method for the preparation of 2-cumaryl-(3')-chromenylium salts is known (DE-OS No. 2,349,960) but it relates only to the preparation of 2-cumaryl-(3')-chromenylium salts which do not possess any amino-functional groups.

Amino-substituted 2-cumaryl-(3')-chromenylium salts have previously not been known.

The object of the invention is to prepare previously unknown amino-substituted 2-cumaryl-(3')-chromenylium salts in an uncomplicated manner.

The task of the invention is to synthesize the previously unknown amino-substituted 2-cumaryl-(3')-chromenylium salts by using simply produced starting materials. The task is solved according to the invention by reacting substituted 3-acetylcumarines of type I ##STR2## in the presence of an acid HY with substituted salicylaldehydes of type II ##STR3## or by reacting 3-chloro-3-cumaryl-(3')-propene-(2)-iminium salts or -aldehydes of type III, respectively ##STR4## where X denotes an oxygen atom or an iminium salt group, in the presence of an acid HY with substituted phenols of type IV ##STR5## so that amino-substituted 2-cumaryl-(3')-chromenylium salts of Type V result, where R.sup.3 and/or R.sup.7 are a dialkyl or cycloalkyl- disubstituted amino group, hydrogen or a hydroxy group, and where R.sup.1, R.sup.2 and R.sup.4 as well as R.sup.5, R.sup.6 and R.sup.8 may be the same or different and are hydrogen, one alkoxy group or two of these substituents together form an aromatic ring and where Y.sup.- is an acid radical as for instance C10.sub.4.sup.-.

The invention will be explained infra by using the amino-substituted 2-cumaryl-(3')-chromenylium salts, listed in the appended tables as examples of execution which were prepared according to the following variations:

0.01 Mol 3-acetyl curmarin of type I is mixed with 25 ml glacial acetic acid, 2 ml perchloric acid (70%) and 0.01 Mol substituted salicylaldehyde of type II. The mixture is heated 25 minutes to gentle boiling. The chromenylium compound of Type V precipitates on cooling, is suctioned off and recrystallized.

The sequence is analogous to variant A except that 15 ml acetic anhydride are used instead of glacial acetic acid and the mixture is heated only 10 minutes to a gentle boil.

0.01 Mol of acetylcumarin of type I and 0.01 Mol substituted salicylaldehyde of type II are dissolved in 20 ml 85% formic acid. Thereafter, hydrogen chloride is bubbled through for 5 hours at room temperature. After consecutively adding 100 ml glacial acetic acid and 30 ml 20% perchloric acid, the chromenylium compound of type V is precipitated by water, suctioned off and recrystallized.

0.01 Mol 3-chloro-3-cumaryl-(3')-propene-(2)-iminium salt of type III (X=.sub.N.sup.+ (CH.sub.3).sub.2 C10.sub.4.sup.-), prepared according to WP C 07 D/209 424 and 0.01 Mol of a substituted phenol of type IV are suspended in 20 ml glacial acetic acid and heated under reflux for one hour. Thereafter, 2 ml 70% perchloric acid is carefully added, and the immediately occurring precipitate of the chromenylium compound of type V is suctioned and recrystallized.

The sequence is analogous to variant D except that 15 ml acetone hydride is used and the mixture is heated only 10 minutes to boiling.

The sequence is analogous to variant D but instead of using 3-chloro-3-cumaryl-(3')-propene-(2)-iminium salts, the 3-chloro-3-cumaryl-(3')-propene-(2)-aldehydes of type III (X=O) are used, prepared according to WP C07 D/209 424.

The examples of execution listed in the table are compounds which were recrystallized from glacial acetic acid. The melting points in all cases lie above 360.degree. C.