: B 2728 (OTTOKEMI) Butylmagnesium chloride, 2.0 M IN DIETHYL ETHER CAS-693-04-9,is a Grignard reagent that can be used to prevent the formation of passivating surface films on Mg electrodes.For the synthesis of lithium tributylmagnesate complex (n-Bu3MgLi) by reacting with n-BuLi.