Oxocarbons and Related Compounds; Part 15. Meerwein-Arylation of Semisquaric Acid and Semisquaric Amides. A General Method for the Preparation of 3-Aryl-4-hydroxy- and 3-Amino-4-aryl-3-cyclobutene-1,2-diones.

Article abstract of DOI:10.1055/s-1990-26946

Meerwein-arylation of semisquaric acid (1) and semisquaric amides 4 has been found to afford general routes to 3-aryl-4-hydroxy-3-cyclobutene-1,2-diones 3 and 3-amino-4-aryl-3-cyclobutene-1,2-diones 5 respectively.