ibuprofen is 4-isobutyl alpha-methyl phenylacetic acid. so i thought you could condense the ethyl ester with diethyl malonate or maybe even ethyl acetate and decarboxylate to get 4-isobutyl alpha-methyl p2p. a guy said that 4-isobutyl alpha-methyl amphetamine was "not bad", but i could use a little more feedback. any comments?

Does "not bad" stands for "not active" and who is this "guy" anyway? Where is your reference or at least a description of any anecdotal source?
I would expect that amphetamine with such a bulky group at the para and even an additional methyl at the beta position would be very much inactive to say the least.

not even getting involved...

but i doubt its as a precursor...