Racemic 3,4-dihydro-2H-1-benzopyran-2-carboxylic acid (I) is resolved into the corresponding enantiomers by recrystallization of the diastereomeric salts with (+)-(R)-alpha-methylbenzylamine, and the desired (R)-carboxylic acid is further esterified with H2SO4/EtOH to furnish the ethyl ester (II). Subsequent reduction of ester (II) with NaBH4 in toluene/EtOH leads to alcohol (III), which is converted into mesylate (IV) employing methanesulfonyl chloride and triethylamine. Mesylate (IV) is finally condensed with 1-(3-aminopropyl)-hexahydro-2-pyrimidinone (V) by heating with CaO at 100 C in THF in an autoclave to provide the title compound