Aminomethinylierung H-aktiver verbindungen in der reihe analgetischer wirkstoffe

Electrophilic attack of the active methylene group in 3-methyl-1-phenyl-5-pyrazolone (2) by s-triazine (1) leads to aminomethinylation of 2 with formation of 3-methyl-1-phenyl-4-aminomethylene-5-pyrazolone (4). Subsequent interaction of 4 with 2 explains the formation of 4,4′-methenyl-bis-[3-methyl-1-phenyl-5-pyrazolone (5). 1-Phenyl-3,5-pyrazolidinedione (6) reacts analogously with 1 forming 1-phenyl-4-aminomethylene-3,5-pyrazolidinedione (7). N,N′-Bis-indanyl-formamidine (9) results from the interaction of 2-amino-indane (8) with 1.