K. G. Nazarenko, N. Shtil, M. Lozinskii
Aug 6, 2007
Citations
0
Influential Citations
10
Citations
Journal
Tetrahedron
Abstract
The reaction of 2-chloro-3,4-dihydro-2H-1,4-benzothiazin-3-ones 1 with enamines is an efficient synthetic method to produce 2-substituted derivatives. The resulting bifunctional compounds such as 6a,b, 7c,d and 8b react with hydrazines to furnish the spiro derivatives of N-aminopyrrole or 3-pyridazinone depending on the direction of the primary nucleophilic attack and the nature of the nucleophile. Under the reaction conditions, spiro pyridazinones 13 are converted into the 3-pyridazinone-4-carboxylic acid derivatives 9 via the 1,4-thiazine ring opening.