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Synthesis of Diketocyclobutenediol

IP.com Disclosure Number: IPCOM000084773D
Original Publication Date: 1976-Jan-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Gadek, T: AUTHOR [+3]

Abstract

Diketocyclobutenediol, more commonly known as squaric acid, is useful as an acid compound and also as a precursor for many dye and photosensitizing compounds. The process of fabrication set forth above provides a simple, efficient, single container process of producing squaric acid.

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Synthesis of Diketocyclobutenediol

Diketocyclobutenediol, more commonly known as squaric acid, is useful as an acid compound and also as a precursor for many dye and photosensitizing compounds. The process of fabrication set forth above provides a simple, efficient, single container process of producing squaric acid.

With reference to the above reactions, the process is carried out as follows. Into a 500 ml flask equipped with a reflux condenser, stirrer, and CaCl(2) drying tube, is placed 25 g of hexachlorobutadiene, 50 g morpholine, and 25 ml toluene. The mixture is heated in an oil bath at a temperature in the range of about 110 to 120 Degrees C for a period of about 7 hours under refluxing conditions.

Subsequently, the material is allowed to cool to room temperature and 200 ml of a buffer solution having a pH of about 4.78 which is 2.0 M in acetic acid and 1.0 M in sodium hydroxide is added.

The mixture is then heated to about 60 Degrees C, and maintained at that temperature for about 16 hours, while stirring continuously.

Then the mixture is allowed to cool and 60 ml of concentrated sulfuric acid is added.

After the addition of the acid is completed, the mixture is again refluxed in the same container, this time for about 24 hours, and then cooled to room temperature. The resulting product is collected by filtration, washed with water and acetone, and air-dried. Without further treatment, a yield of about 45% squaric acid is obtained.

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