Abstract: Process for preparing Naproxen via a sequence of stereospecific reactions which comprises: condensation of 1-chloro-2-methoxy-naphthalene with a (S)-2-halo-propionyl halide according to the Friedel-Crafts reaction, ketalization of the thus obtained (S)-2-halo-1-(5'-chloro-6'-methoxy-2'-naphthyl)propan-1-one, rearrangement of said ketal to afford an ester, hydrolysis of the ester and removal of the chlorine atom in 5-position by hydrogenolysis.New (S) 2-halo-1-(5'-chloro-6'-methoxy-2'-naphthyl)propan-1-ones.

Abstract: Process for preparing Naproxen via a sequence of stereospecific reactions which comprises: condensation of 1-chloro-2-methoxy-naphthalene with a (S)-2-halo-propionyl halide according to the Friedel-Crafts reaction, ketalization of the thus obtained (S)-2-halo-1-(5'-chloro-6'-methoxy-2'-naphthyl)-propan-1-one, rearrangement of said ketal to afford an ester, hydrolysis of the ester and removal of the chlorine atom in 5-position by hydrogenolysis.New (S) 2-halo-1-(5'-chloro-6'-methoxy-2'-naphthyl)-propan-1-ones.

Abstract: A process for the resolution of (.+-.) 2-[2'-(p-fluorophenyl)-5'-benzoxazolyl]-propionic acid, indicated for brevity as (.+-.)-FBP, by treatment with (-)N-R-glucamine, indicated for brevity as NRG and in which R is an alkyl or cycloalkyl radical, followed by fractional crystallization of the mixture of the diastereoisomer salts obtained, and by separation of the precipitate, from which, by hydrolysis, (.+-.)-FBP is obtained with the required purity characteristics. The levorotatory antipode, (-)-FBP, is racemized, preferably by the formation of one of its esters, which is then hydrolyzed to give the (.+-.)-FBP, which is recycled to the treatment with NRG. (+)-FBP and (-)-FBP salts with NRG obtained by said process.