Sterification of 1,3-dichloro-2-propanol (I) with p-chlorophenoxyisobutyric acid (II) forms 1,3-dichloro-2-propanol 2-p-chlorophenoxyisobutirate (III), which, by reaction with the sodium salt of nicotinic acid, is transformed into trihydroxipropane 2-p-chlorophenoxyisobutyrate-1,3-dinicotinate.