Abstract: The present invention provides a method to prepare alkyl-4-[2(phthalimido)-ethoxy]-acetoacetate which are useful in the manufacture of anti-hypertensive and anti-ischaemic drugs by reacting 2(phthalimido)-ethoxyacetic acid with thionyl chloride and then reacting the acid chloride product obtained with Meldrums acid.

Abstract: A process for preparing a 2R-hydroxy-3-[(2-amino-phenylthio)]-3-[(p-alkoxyaryl)] propanoic acid alkyl ester of formula (V) wherein R is an alkyl, or benzoyl residue, R1 is hydrogen, an alkyl, alkoxy, aryloxy, phenyl, naphthyl, or hydroxy residue, and R2 and R3 are independently of each other hydrogen, and alkyl, alkoxy, alkylamino, alkylthio, aryl, or halogen residue, which comprises refluxing 2-aminothiophenol, or 2-aminothionaphthol with a compound of Formula (IV) that is 5S-(p-alkoxyphenyl)-4R-carboalkoxy-1,3,2-dioxathiolane-2-oxide when X is S, or the corresponding cyclic carbonate, in the presence of an organic solvent and an inert atmosphere, and recovering the resultant compound of Formula (V).

Abstract: A compound of formula (IV) ##STR1## wherein R.sup.1 is hydrogen, an alkyl, alkoxy, alkylamino, alkylthio, aryl, aryloxy, or halogen residue; R is an alkyl, or aryl residue, and X is S or C, which is a valuable intermediate for producing Diltiazem.