Download PDF
Synthesis 1987; 1987(2): 134-137
DOI: 10.1055/s-1987-27861
paper
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Oxokohlenstoffe und verwandte Verbindungen; 12. Mitteilung. Eine einfache Synthese von 3-Hydroxy-3-cyclobuten-1,2-dion ("Semiquadratsäure"; "Moniliformin") und dessen Umsetzung mit Aminen

Arthur H. Schmidt* , Harry Maibaum
  • *Abteilung für Organische Chemie und Biochemie, Fachhochschule Fresenius, Kappellenstraße 11-15, D-6200 Wiesbaden, West Germany
Further Information

Publication History

Publication Date:
12 September 2002 (online)

  PDF Download  Permissions and Reprints All articles of this category

Oxocarbons and Related Compounds; Part 12. A Simple and Efficient Synthesis of 3-Hydroxy-3-cyclobutene-1,2-dione ("Semisquaric Acid"; "Moniliformin") and its Reaction with Amines Starting with squaric acid (1), semisquaric acid (4) has been synthesized in a 54% overall yield. In contrast to a literature report semisquarie acid (4) reacts with ammonia (5a) and aniline (5b) in the cold to give the ammonium-semisquarates 6a and 6b, respectively, and not the corresponding semisquaric amides. Accordingly, several primary, secondary, and tertiary amines react with 4 to afford the semisquarates 6c-k. Semisquaric amide (8) has been obtained unambiguously by the catalytic hydrogenation of 3-amino-4-chloro-3-cyclobutene-1,2-dione (7).