Egon Spengler fraud, violating their judicial restraining order, and malicious mischief by judge Stephen Wexler (whom Egon said was known as "The Hammer"). While angrily insulting the trio judge Wexler inadvertently released the ghosts of the Scoleri Brothers; two murderers he sentenced to death by the electric chair. During the chaos judge Wexler dismisses the charges against the Ghostbusters, and rescinds the judicial restraining order allowing Egon, Ray, and Peter to capture the ghosts, effectively putting the Ghostbusters back in business. Egon had a dry sense of humor, of which he used on Peter to bewilder him, and smirked at his friend's
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