A regioselective approach to 5-substituted-3-amino-1,2,4-triazines.
Nucleophilic displacement of readily available alpha,alpha-dibromoketones with excess morpholine gave the corresponding ketoaminals, which upon condensation with aminoguanidine in MeOH in the presence of AcOH afforded 5-substituted-3-amino-1,2,4-triazines in >95% regioselectivity and 45-76% isolated yield. [reaction: see text]
Limanto
John
J
Department of Process Research, Merck Research Laboratories, Merck & Co., Inc., P.O. Box 2000, Rahway, NJ 07065, USA. john_limanto@merck.com
Desmond
Richard A
RA
Gauthier
Donald R
DR
Devine
Paul N
PN
Reamer
Robert A
RA
Volante
R P
RP