Disclosed is a process for manufacturing a compound of formula (8) (such as N-[trans-4-{ 4-(cyclopropylmethyl)-piperazin-1-yl} cyclohexyl]-3-methoxy-4-nitrobenzamide), wherein R5 denotes alkyl, alkyl-cycloalkyl or cycloalkyl； R4 denotes hydrogen or a group selected from cyano, hydroxy, alkyl, alkyloxy and alkylthio, wherein a compound of general formula (7) (such as 3-methoxy-4-nitro-benzoic acid), optionally converted into an acyl halide compound, is reacted with the amine compound of formula (6) (such as 1-(cyclopropylmethyl)-4-(trans-4-aminocyclohexyl)-piperazine / trans-4-(4-cyclopropyImethyl-piperazin-1-yl)-cyclohexylamine), using an alkali or alkaline earth hydroxide as base (e.g. sodium hydroxide) and a protic solvent (such as water). Also disclosed is a process for the reduction of compounds such as N-[trans-4-{ 4-(cyclopropylmethyl)-piperazin-1-yl} cyclohexyl]-3-methoxy-4-nitrobenzamide by hydrogenation to form intermediates such as N-[trans-4-{ 4-(cyclopropylmethyl)-piperazin-1-yl} cyclohexyl]-3-methoxy-4-amino-benzamide, and their subsequent use in the preparation of pharmaceutical dihydropteridinones of general formula (11), which includes compounds such as N-[trans-4-{ 4-(cyclopropylmethyl)-piperazin-1-yl} cyclohexyl]-3-methoxy-4-{ ((R)-7-ethyl-8-isopropyl-6-oxo-5-methyl-7,8-dihydro-5H-pteridin-2-yl)amino} -benzamide.
