Egon Spengler the love interest of Janine Melnitz, the Ghostbusters' secretary, in the first film and both animated series ("Ghostbusters II" excluded their romance due to Ramis' dislike of the subplot, thus having Melnitz date Louis Tully instead). Spengler sometimes appears to be unaware of Melnitz's romantic interest in him, but at times he displays having similar feelings for her, such as when he gave her a geranium as a gift when she expressed an interest in plants (which backfired horribly when it was revealed that the geranium was possessed by a ghost and nearly destroyed her apartment, along with much of
Pictet–Spengler reaction tetrahydroisoquinoline synthesis. Reaction conditions are generally harsher than the indole variant, and require refluxing conditions with strong acids like hydrochloric acid, trifluoroacetic acid or superacids. Instead of catalyzing the Pictet-Spengler cyclization with strong acid, one can acylate the iminium ion forming the intermediate "N"-acyliminium ion. The "N"-acyliminium ion is a very powerful electrophile and most aromatic ring systems will cyclize under mild conditions with good yields. Tadalafil is synthesized via the "N"-acyliminium Pictet–Spengler reaction. This reaction can also be catalyzed by AuCl and AgOTf. When the Pictet–Spengler reaction is performed with an aldehyde other than formaldehyde, a new chiral center