FISSION OF As-As BONDS IN ELEMENTAL ARSENIC BY ALKALI METALS IN LIQUID AMMONIA. PREPARATION OF DIALKYL AND TRIALKYL ARSINES

Suspensions of alkali arsenides MAsH 2 (M˭ Li, Na or K) in liquid ammonia have been prepared by dropwise addition of t-butyl alcohol (2 equiv.) to a mixture of dissolved metal (3 equiv.) and powdered arsenic. Subsequent reaction with an alkyl halide gave dialkyl arsines in good yields as main products in the cases of LiAsH 2 and NaAsH 2 , and trialkyl arsines in excellent yields in the case of KAsH 2 .