The Baylis-Hillman reaction between N-Boc-alaninal (I) and methyl acrylate (II) in the presence of DABCO yields the allylic alcohol adduct (III). Subsequent Mitsunobu coupling with acetic acid leads to the rearranged allylic acetate (IV). Acidic Boc group cleavage in (IV) then gives the amino ester intermediate (V).

The pyrimidinone acetaldehyde (VI) is oxidized to the corresponding acid (VII) by means of sodium chlorite. Then, coupling of acid (VII) with amino ester (V) using DCC and HOBt provides the target amide.