Photochromic 2h-chr0menes annulated at c5-c6 and their methods of preparation

Abstract

Described herein are C5-C6 annulated naphthopyrans that possess at least one electron-withdrawing group. The compounds possess desirable properties such as increased fading kinetics. Also described herein are new methods for synthesizing 2H- chromenes annulated at C5-C6. The methods involve less stringent reaction conditions as well as provide increased reaction yields. The methods permit the synthesis of a wide variety of substituted naphthopyrans that can be temperature sensitive and were not possibly synthesized with previous synthetic routes.

Description

[0001] Cross References to Related Applications [0002] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61 / 092,191, filed August 27, 2008. Background technique [0003] C 5 -C 6 Cyclic naphthopyrans are photochromic compounds capable of changing color under the influence of poly- or monochromatic light, such as UV light. When the irradiation is stopped, or under the influence of temperature and / or poly- or monochromatic light different from the original light, the compound returns to its original color. C 5 -C 6 Cyclic naphthopyrans are used in various fields, for example in the manufacture of spectacle lenses, contact lenses, sunglasses, optical filters, optical cameras or other optical devices as well as observation devices, glazing and decorative objects. C 5 -C 6 Cyclic 2H-chromenes in some cases have a neutral gray or brown color after UV irradiation, which is of particular interest for use in photochromic mirror...

AI Technical Summary

Problems solved by technology

For example, the Friedel-Crafts annulation reaction proceeds at 200 °C, and the removal of the cyano group involves much higher temperatures (220 °C), which is critical for many temperature-sensitive substituents present on naphthopyrans, such as electron-withdrawing groups can cause problems

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