K. Esses-reiter et J. Reiter, Attempted synthesis of a Tenidap isomer and formation of an unexpected stable water adduct, J HETERO CH, 37(4), 2000, pp. 927-933
An attempt to synthesize the Tenidap isomer 13 was performed starting from
2-ethoxy-5-chloroindole (9). The acylation and carbamoylation reactions of
9 led to the expected intermediate 12, however the hydrolysis of 12 in acid
ic or alkaline media did not yielded the expected 13. Instead an unusually
stable water adduct 18 or the cleavage product 16 was formed. The formation
of the unexpectedly stable water adduct 18 was caused by the steric and el
ectronic effect of the thienoyl group in position 1 as proved by the hydrol
ysis of 10 and 16.