SYNTHESIS OF 6-CYCLOALKYLCARBONYL-2(3H)-BENZOTHIAZOLONES VIA 6-TRIBUTYLTIN INTERMEDIATES

摘要

6-Cycloalkylcarbonyl-2(3H)-benzothiazolones cannot be prepared by classical Friedel-Crafts acylation with the corresponding cycloalkylcarbonyl chlorides.We have explored new way via stille coupling from the tributyltin intermediates which were synthesised by protection of the NH group with ethylmethyl ether or potassium salt of the corresponding 6-bromo-2-(3H)-benzothiazolone.The stille coupling reaction of these tributyltin intermediates with the desired cycloalkylcarbonyl chlorides followed by deprotection of the NH group,afforded the corresponding 6-cycloalkylcarbonyl-2(3H)-benzothiazolones.