The process for preparing butadiene from n-butane comprises the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone; C) compressing in at least one first compression stage and cooling the gas stream b; D) absorbing the butenes and the stream c2 comprising butadiene, n-butane, hydrogen and water vapor, with or without inert gases and with or without carbon oxides, with a selective solvent; E) extractively distilling the selective solvent; F) distilling the selective solvent; G) feeding stream f and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butenes.