Process for the Preparation of 4-Aminopyrazole Derivatives
申请人:Hill George Beresford
公开号:US20080269500A1
公开(公告)日:2008-10-30
Processes for the preparation of 4-aminopyrazole and derivatives thereof, such as those of formula (C), which are useful as intermediates in the preparation of pharmaceutical compounds; to certain compounds used in these processes; and to processes for the preparation of said compounds.
Two New Syntheses of a 4-Aminopyrazole: Condensation of an N-Substituted Vinamidinium Salt with a Functionalized Hydrazine
作者:George Hill、Andrew Mortlock
DOI:10.1055/s-2007-966054
日期:2007.6
are described. Both routes avoid the potentially explosive precursors that were used in the previously patented route. A salt of a vinamidinium cation previously used in 5-aminopyrimidine synthesis was condensed with a protected hydrazine salt leading to a 4-aminopyrazole. Buchwald-type amination coupling has also been shown to yield the same compound.