The chlorination of 2-phenyl-3-methyl-4-oxo-4H-1-benzopyran-8-carboxylic acid (I) with thionyl chloride gives the corresponding chloride (II), which is esterified with 1,1-dimethyl-2-(1-piperidinyl)ethanol (IV), obtained by alkylation of excess piperidine (III) with 1-chloro-2-methyl-2-propanol. Rec 15/2053 is obtained as the hydrochloride.