The silylation of 4-acetoxy-2-pyrrolidone (I) with trimethylchlorosilane (II) by means of triethyl amine in THF gives the corresponding N-trimethylsilyl derivative (III), which is condensed with 4-methoxybenzoyl chloride (IV) by means of NaHCO3 in THF yielding 1-(4-methoxybenzoyl)pyrrolin-2-one (V). Finally, this compound is reduced with H2 over Pd/C in ethyl acetate.
The condensation of 4-aminobutyric acid (VI) with acid chloride (IV) by means of NaOH in water gives 4-(4-methoxybenzoylamino)butyric acid (VII), which is then cyclized by means of P2O5 in phosphoric acid.
The condensation of 6-methoxy-2-naphthaldehyde (I) with acetone by means of NaOH in water gives 4-(6-methoxy-2-naphtyl)-3-buten-2-one (II), which is reduced with H2 over Pd/C in ethyl acetate.
By reaction of 2-pyrrolidinone (I) with p-methoxybenzoyl chloride (II) by means of triethylamine in ether or sodium hydride in DMF.