合成路线1

The hindered base, diisobutylamine, was used in the Stork enamine synthesis of valeraldehyde (I) with allyl bromide to yield the desired aldehyde (II) following acidic hydrolysis and subsequent hydrogenation. Acid-catalyzed annelation of (II) with methyl vinyl ketone provided 4,4-dipropylcyclohex-2-enone which upon hydrogenation gave (III). Piperidine-catalyzed condensation of ethyl cyanoacetate with (III) gave cyanoester (IV). Michael addition of KCN followed by acidic hydrolysis gave diacid (V). Treatment of diacid (V) with acetic anhydride gave desired anhydride (VI), which was condensed with N,N-dimethylaminopropylamine to yield the desired imide (VII). Lithium aluminum hydride reduction of the imide (VII) gave the desired diamine which was treated with anhydrous HCl/ethanol to give the required dihydrochloride salt, SK&F 105685.