Synthesis of squaric acid
CA 1071237 A · Owner: International Business Machines Corporation · Inventors: Sclove, David B.; Vollmer, Robert L.; Gadek, Thomas R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure Squaric acid is prepared by reacting hexachlorobutadiene with an excess of morpholine in the presence of an aromatic hydrocarbon solvent while maintaining the temperature between 110°C and 120°C, and then converting the resulting 1,1,3-trichloro-2,4,4-trimorpholino-butadiene to 3-morpholinotrichloro-2-cyclobuten-1-one which in turn is, hydrolyzed in the presence of strong acid to produce the desired squaric acid.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted February 5, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 5, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.