Abstract
A series of novel 3-aryl-(3,3-diaryl-3H-naphtho[2,1-b]pyran-8-yl)-3H-naphtho[2,1-b]pyrans has been accessed from 6-bromo-2-naphthol via a four step transformation. Acylation of the dianion derived from the treatment of 6-bromo-2-naphthol with n-butyllithium with Weinreb amides and subsequent reaction with a 1,1,-diarylprop-2-yn-1-ol gave 8-aroyl-3H-naphtho[2,1-b]pyrans in good yield. Addition of lithium trimethylsilylacetylide to the foregoing 8-aroylnaphthopyrans proceeded smoothly with base-mediated desilyation to afford the target bi-naphthopyrans upon acid-catalysed reaction with 2-naphthol. Preliminary evaluation of the photochromic response of the new bi-naphthopyrans revealed reversible independent naphthopyran ring-opening leading to a complex photochromic signature.
Original language | English |
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Pages (from-to) | 239-250 |
Number of pages | 12 |
Journal | Dyes and Pigments |
Volume | 113 |
Early online date | 28 Aug 2014 |
DOIs | |
Publication status | Published - 1 Feb 2015 |