Organophosphorus compounds. XII. A new synthesis of phosphindolines and phosphindoles

Abstract

The reaction of 2-phenylethylphosphonous dichloride with zinc chloride at 170º followed by hydrolysis with concentrated hydrochloric acid, and oxidation, gave 72% of 1-hydroxyphosphindoline 1-oxide. Treatment of the derived phosphinic chloride with vinyl magnesium bromide at -40º afforded 1-vinylphosphindoline 1-oxide which underwent addition of dimethylamine to yield 1-(2'-dimethylaminoethyl)phosphindoline 1-oxide. The conversions of 1-chlorophosphindoline 1-oxide into 1-ethyl- and 1-phenyl-phosphindoline 1-oxide are described. Bromination of l-methoxy- phosphindoline 1-oxide with N-bromosuccinimide followed by dehydrobromination afforded 1-methoxyphosphindole 1-oxide. 1-(2'-Dimethylaminoethyl)phosphindoline 1-oxide and the corresponding phosphine sulphide were assayed for analgetic activity.