The synthesis of the 14C and 2H-isotopomers of (R)-N-[2-(2'-ethoxyphenoxy)-ethyl]-N-2-[3-(4'-methoxy-3'-sulfonamido)-phenyl ]-propylamine hydrochloride, an α1-adrenoreceptor antagonist

The synthesis of [14C]- and [2H]-labeled LY253351 (YM12617-1), a potent α1-receptor antagonist, which is potentially useful in the treatment of benign prostatic hypertrophy (BPH) is described. The [14C]-isotopomer was synthesized from [14C]-potassium cyanide in nine steps in 1.5% radiochemical yield. One of the key intermediates, [14C]-4-methoxyphenylacetone, was synthesized from [14C]-4-methoxyphenylacetyl chloride by a Pd(0)-catalyzed reaction with tetramethylstannane. The [2H]-labeled material was synthesized by a Pd/C catalyzed reductive amination with deuterium gas. (author)