Treatment of ethyl 4-bromobutylphosphonochloridate with phenylmagnesium bromide, followed by acid-catalysed hydrolysis of the product, gave 4- bromobutyl(phenyl)phosphinic acid. This was converted into the corresponding phosphinamide by treatment with thionyl chloride and then with aqueous ammonia. Cyclodehydrobromination with sodium hydride in warm xylene then gave a good yield of 2-phenylperhydro-1,2- azaphosphorine 2-oxide. Some other routes to this compound were investigated.

Die Behandlung des Brombutylphosphonsäurechlorids (I) mit Phenyl‐MgBr und darauffolgende säurekatalysierte Hydrolyse führt zu der Phenylphosphinsäure (IIb).