Alcoholysis of medicinally active 5-aminodibenzo(a,d)cycloheptenes

The rate constants for alcoholic solvolysis of the hydrochloride salts of diethylaminodibenzo(a,d)cycloheptene and related amino congeners were determined. The objective was a study of the comparative ease of cleavage of the C-N amino linkage by various aliphatic alcohols. The interaction of protonated amines of this series with alcoholic hydroxyls presumably leads to formation of the corresponding ethers in a manner somewhat analogous to alkoxide reaction with alkyl bromides. The methyl ether produced from solvolysis of diethylaminodibenzocycloheptene hydrochloride was isolated and identified. Methanol appears to react somewhat more rapidly with the amine hydrochlorides than other aliphatic alcohols. The latter produce almost invariant velocity constants with a given amine hydrochloride. The exception was tertbutanol, which resulted in Kobs values about one-third of those given by the other alcohols. Some velocity constants in formic and acetic acids were evaluated. Generation of carbonium ions of appreciable lifetime was indicated in formic acid by the formation of a highly colored (red-violet) solution. This color may be a manifestation of the dibenzotropylium ion.