javas post regarding methylenation, cannot formic acid be used directly?

meaning mda>mdma, as the desired substrate.

a lazy post by me, apologies. its just i have formic to hand.

i'm not sure if it works or not the paper does'nt explicitly say sec amines.
it was just an idea to kinetically controll the reaction by adjusting stoichiometry and rxn times experiment is king.
one would speculate that adding the amine portionwise as the reaction goes along at a rate that maintains gas evolution would keep the amine scarce so it does'nt react with itself.
actually i got that backwards keep the amine excess and then add the formalin portionwise to keep it scarce since the reaction produces co2 gas this is a good indicator of rate.
one could set a dropping funnel to add the formalin at a speed that maintains the reaction.

either way you'll still wind up with dialkyl amines as an impurity.

klute's way from SM works well for almost all amines. generate the benzalimine from mda+benzaldehyde, react with methyl tosylate (easily made from tosyl chloride + methanol), then hydrolyze with acid the imine back to the amine and voila -> secondary amine!