Synthesis and Properties of 4-Alkoxy-5-imino-1,4-thiazinan-3-ones

Article abstract of DOI:10.1002/ardp.19853180909

2-(Cyanomethylthio)-2,2-diphenylacetic acid (5a) reacts with alkoxyamines 2 and dicyclohexylcarbodiimide via the not isolated N-alkoxyamides 6a,b to yield the 4-alkoxy-5-imino-1,4-thiazinan-3-ones 7a,b.Reactions of the mono- and unsubstituted acids 5b,c with 2a-c afford primarily the N-alkoxyamides 6c-f, which undergo cyclisation to 7Ac-f in the presence of hydrogen chloride.Treatment of 7Ad,Af with sodium carbonate leads to the unstable bases 7d,f, which are converted to 8 with isocyanates.During the hydrolysis of 7Ad in hot ethanol, ring cleavage is observed leading to the diamide 9, whereas 7Ab is transformed under the same conditions to 4-benzyloxy-2,2-diphenyl-1,4-thiazinan-3,5-dione (10).