Huiping Zhang, S. H. Watterson, Zili Xiao
Jun 14, 2010
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0
Influential Citations
3
Citations
Journal
Organic Process Research & Development
Abstract
An efficient synthesis of 6-[(5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non-7-yl]nicotinic acid 1 is described. This new process involves an in situ protection of 6-chloronicotinic acid as trimethylsilyl ester followed by coupling with spirocyclic hydantoin core 2 to give the target product in 89% overall yield after one-pot deprotection and final API recrystallization.