Potassium Carbonate → 1-(4-Hydroxyphenyl)-4-(3-cyano-4-methyl-6-phenylpyrid-2-yl)piperazine

Participants

Reaction Conditions

Reaction Steps

12.26 g (36 mmol) of 1-(4-hydroxyphenyl)piperazine dihydrobromide, 8.24 g (36.1 mmol) of 2-chloro-3-cyano-4-methyl-6-phenylpyridine and 7.46 g (54 mmol) of powdered K2CO3 in 135 ml of absolute DMF were reacted at 90° C. according to the procedure described in Example 20. The mixture was subsequently stirred for 10 hours at 110° C. After removal of the DMF by distillation, the residue was taken up in CH2Cl2 /water. After thorough mixing, separating the phases and extraction of the aqueous solution, the CH2Cl2 extracts were combined, dried and evaporated. The crystalline residue (14.6 g) was recrystallized three times as follows. The substance was dissolved in a boiling mixture of CH2Cl2 /CH3OH 1:1, and the majority of the CH2Cl2 was then removed by distillation. A product crystallized out of the CH3OH solution obtained, and was filtered off under suction and again recrystallized in this fashion. Further impure substance was isolated from the mother liquors by concentration etc, and this was finally recrystallized again as described above. In this fashion, 6.82 g (=51% yield) of 1-(4-hydroxyphenyl)-4-(3-cyano-4-methyl-6-phenylpyrid-2-yl)piperazine, melting point 207°-08° C., were obtained;

Provenance & Evidence