Effect of Bromination on the Pharmacological Properties of Methyl 1-Allyl-4-Hydroxy-2,2-Dioxo-1H-2 lambda(6),1-Benzothiazine-3-Carboxylate

摘要

An x-ray crystal structure analysis found that the bromination of methyl 1-allyl-4-hydroxy-2,2-dioxo-1H-2 lambda(6),1-benzothiazine-3-carboxylate by Br-2 in glacial HOAc involved not heterocyclization but classical addition of Br-2 to the unsaturated allyl bond, in contrast with structurally similar alkyl 1-allyl-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates. Pharmacological tests showed that removal of the double bond from the 1-N-alkyl moiety in the esters was associated with a decrease of analgesic activity.