Related Experiment Video
Updated: Aug 15, 2025

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines
Published on: January 3, 2018
Rapid access to polycyclic thiopyrylium compounds from unfunctionalized aromatics by thia-APEX reaction
Kou P Kawahara1, Hideto Ito1, Kenichiro Itami1,2
1Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan. Itamiito.hideto.p4@f.mail.nagoya-u.ac.jp.
Abstract:
We developed a sulfur-embedding annulative π-extension (thia-APEX) reaction that could construct a sulfur-embedding cationic hexagonal aromatic ring, thiopyrylium, onto unfunctionalized aromatics in one step. The key of thia-APEX is the use of S-imidated ortho-arenoyl arenethiols, and a variety of π-extended thiopyryliums can easily be synthesized. The synthesized thiopyryliums showed diverse absorption and emission properties over the visible light to NIR region, depending on minor structural differences.
Related Concept Videos
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Nucleophilic Aromatic Substitution: Elimination–Addition
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Preparation of Alkynes: Dehydrohalogenation
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

