Patent · US Expired

7-Dimethylamino-3-substituted-2,2'-spirobi[2H-1-benzopyrans]

US4342696A · kind A · utility

0Cited by
9References
2Claims
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Assignee

Inventors

Key dates

Filing dateJun 25, 1981
Grant dateAug 3, 1982
Priority date—
Expiry dateJun 25, 2001

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S430/156
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

Substituted spirobi[2H-1-benzopyrans] particularly suitable for use as precursors to stable colored pyrylium salts are disclosed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.