We report a straightforward synthesis. in high yields, of the new ligands bis(-Z(alkylarsinoethyl) (amine, useful polydentate ligands for Inorganic Chemists because they contain hard and soft donor atoms with varying degrees of a-basicity and w-acidity, thus being of interest to study their behaviour in coordination chemistry. Additionally, the insertion of metal centres into a N-H bond is a reaction of important development in the catalytic process involving the homologation of ammonia and mines with alkenes or carbon monoxide.
It is noteworthy that ligands bisl-2(dialkylarsinoethyl)(amine are rare although the corresponding phenyl compounds have been synthesized firstly by Sacconi' . This preliminary communication describes the synthesis of bisl-2(dimethylarsinoethyl) lamine, a "model example" chosen among this family of products. The corresponding analogous dialkylarsino reacts as well as dimethylarsino, giving similar experimental observations and results.
Our initial attempt was to treat the THF solution of dimethyl-arsenide sodium directly with the hydrochloride bisI-Z(chloroethy1) lamine. Despite the yield of the desired product being 65%. the reaction consumed 3 moles of dimethylarsenide sodium. with a very slow reactional rate. expressed by the length of time (20 hrs) to have the high level of conversion to the respective product. It is noteworthy that among the resultant products. there is the poisonous product : dimethylarsine ( b . ~. 34'C).
It appears to be more efficient to liberate the free mine with aqueous basic solution, then making the addition to 2 moles of dimethylarsenide sodium solution. The yield of III reached 81% after 5 hrs stirring of the reaction mixture. In addition, the formation of dimethylarsine is to be avoided.