in the case of reductive alkylation the nh compound is reacted with a carbonyl compound and a hydrogen source the hydrogen source may include hydrogen over a palladium or platinum catalyst or nabh 3 cn or formic acid at elevated temperatures where the carbonyl compound is formaldehyde then r c is methyl acetaldehyde then r sup c is ethyl benzaldehyde then r c is benzyl and acetone then r c is isopropyl in the case of r b the desired substituents may be obtained from the appropriately substituted starting materials again specifically in flow sheet aa starting compound aa1 is appropriately substituted with desired r b in flow sheets ab ac ad and ae starting compounds ab5 ac1 ad1 and ae1 are appropriately substituted of course it is clear in the case of both r c and r b that obtaining these desired substituents involves the use of conventional chemistry with relatively well known reactants in the case of r a there is greater variation in both the substituent itself and the substrate to which it is attached and thus further description is necessary the pyridine and thiophene equivalents to trans cinnamoyl chloride compounds aa3 ab2 and ac5 or 1 pyridyl trans buta 1 3 diene equivalent to compounds ad1 or ae1 or 1 thienyl trans buta 1 3 diene equivalent to compounds ad1 or ae1 are r a2 substituted where r a2 is halogen or c 1 4 alkyl each of the r a2 substituents may be synthesized on the thienyl or pyridyl starting material and.