The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1976
Filed:
Aug. 18, 1975
Yulan C Tong, Walnut Creek, CA (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Insoluble association products are formed when solid 2,3-diamino-5,6-dihalopyrazines are contacted with liquid ketones of the structure R.sup.1 --CH.sub.2 --CO--CH.sub.2 --R.sup.2, wherein R.sup.1 and R.sup.2 are both H or together constitute a polymethylene chain of from 2 to 4 carbons. The isomeric 2,6-diamino-dihalopyrazines dissolve in the ketones. Thus, mixtures of the solid 2,3-diamino-dihalopyrazines with their isomers and/or other ketone-soluble materials can be resolved by contacting the mixtures with ketones of the preceding structure and separating the resultant solid and liquid phases. The association products constitute a novel composition of matter.