Synthesis and Unexpected Transformation of 5-[(1,3-Dioxolan-2-ylmethyl)sulfanyl]-1H-pyrrol-2-amine into 5-{[2-(2-Hydroxyethoxy)ethenyl]sulfanyl}-1H-pyrrol-2-amine in the Presence of a Superbase.

Successive one-pot reactions of monolithiated N,N-diethylprop-2-yn-1-amine with 2-(ethenyloxy)-ethyl isothiocyanate and 2-(bromomethyl)-1,3-dioxolane afforded 5-[(1,3-dioxolan-2-ylmethyl)sulfanyl]-1[2-(ethenyloxy)ethyl]-N,N-diethyl-1H-pyrrol-2-amine in 91% yield. In the system t-BuOK–DMSO at room tem-perature (1 h), the product was converted to 1-[2-(ethenyloxy)ethyl]-N,N-diethyl-5-{[2-(2-hydroxyethoxy)-ethenyl]-sulfanyl}-1H-pyrrol-2-amine (yield 68%) instead of expected 1-vinyl derivative. [ABSTRACT FROM AUTHOR]