Yes, I know how to compute (calculate) my yield. I have performed alkylations of P2P and MDP2P and received in excess of 95% mole-to-mole yield after gassing, on more than one occasion. Of course, I was using my method, which involved that overhead stirrer so all of the aluminum was exposed to the Schiff base. No wonder so many of you guys end up with shitty yields. If you would start off with PURE precursors and perform the reaction CORRECTLY - and that means by ensuring that the ENTIRE surface of the aluminum comes into contact with the Schiff base, maybe you would receive a 95%+ yield too.