Butanenitrile may be prepared by heating

${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Cl}+\mathrm{KCN}\to {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CN}$

So, from the above reaction it is clear that butanenitrile can be prepared by n-propyl alcohol with $\mathrm{KCN}$.