Egon Spengler a bronze bust of Harold Ramis as the film's version of Spengler is seen just as Erin Gilbert leaves her office. During the credits of "Ghostbusters", the words "For Harold Ramis" are seen. Spengler's hair was changed from brown in the films (Ramis' natural hair color) to a blond pompadour in the animated series (Spengler wore his hair in a ponytail on "Extreme Ghostbusters"). This was reportedly done due to legal issues concerning character / actor likenesses. Despite his leanings toward science, Spengler has a family history of witchcraft (three ancestors, Zedekiah, Eli and Ezekiel, were wizards), of which he
Pictet–Spengler reaction hydrochloric acid forming a tetrahydroisoquinoline. Like the Mannich reaction, aldehydes give good yields while ketones tend to give lower conversion. The Pictet–Spengler reaction has been applied to solid-phase combinatorial chemistry with great success. An analogous reaction with an aryl-β-ethanol is called Oxa-Pictet–Spengler reaction The reaction mechanism occurs by initial formation of an iminium ion (2) followed by electrophilic addition at the 3-position, in accordance with the expected nucleophilicity of indoles, to give the spirocycle 3. After migration of the best migrating group, deprotonation gives the product (5). Replacing an indole with a 3,4-dimethoxyphenyl group give the reaction named the Pictet–Spengler