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Abstract

A photochromic grey coloring 2H-naphtho[1,2-b]pyran of formula (1) wherein R.sup.1 is selected from mono-, di- or poly-substituted aryl groups, mono-, di- or poly-substituted naphthyl groups and mono-, di- or poly-substituted heteroaryl groups, wherein at least one substituent is a nitrogen containing group, including amino, C.sub.1 -C.sub.20 and C.sub.6 -C.sub.20 alkylamino, C.sub.1 -C.sub.20 and C.sub.6 -C.sub.20 dialkylamino, C.sub.2 -C.sub.20 dialkenylamino, C.sub.2 -C.sub.20 or C.sub.4 -C.sub.20 di(polyalkenyl)amino, arylamino, diarylamino, C.sub.1 -C.sub.20 alkylarylamino, tetra (C.sub.1 -C.sub.10 linear or branched alkyl) guanidino and cyclic-amino groups and at least one of R.sup.7 and R.sup.9, which may be the same or different, is selected from C.sub.1 -C.sub.20 N alkylamino C.sub.1 -C.sub.20 N-alkylamido, C.sub.1 -C.sub.20 N,N-dialkylamido, amido, nitro, amino, C.sub.1 -C.sub.20 alkylamino, C.sub.1 -C.sub.20 dialkylamino, C.sub.2 -C.sub.20 dialkenylamino, C.sub.4 -C.sub.20 di(polyalkenyl)amino, arylamino, diarylamino, C.sub.1 -C.sub.20 alkylarylamino, or cyclicamino groups. The compounds may be combined with a polymeric host material such as plastic or glass to make a sunglass lens, an ophthalmic lens or a window. The compounds may also be included in an ink or a fuel.

First Claim