Observations on the synthesis of photochromic naphthopyrans

Christopher D. Gabbutt, B. Mark Heron, Alicia C. Instone, David A. Thomas, Steven M. Partington, Michael B. Hursthouse, Thomas Gelbrich

Research output: Contribution to journalArticle

74 Citations (Scopus)

Abstract

1-Naphthol reacts with 1,1-diarylprop-2-yn-1-ols 5a,b, under alumina catalysis, by two pathways to give the photochromic naphtho[1,2-b]pyrans 6a,b, together with the propenylidenenaphthalenones 7a,b, representatives of a new class of merocyanine dyes. With 2-methyl-1-naphthol, formation of the photochrome is suppressed; the only products are merocyanines 7c,d. The cyclocondensation of 2-naphthol with 5a,b proceeds much more efficiently, to give the naphtho[2,1-b]pyrans 14a,b. Pyran formation is not suppressed from either 1-bromo- or 1-(4 -methoxyphenyl)-2-naphthol; reaction with 5a,b merely results in expulsion of the C-1 substituent. An alternative pathway supervenes in the reaction of 1-methyl-2-naphthol with 5a to give the benz[e]indanone 17, the constitution of which was determined by X-ray crystallography. Reaction of the 1,3,3-triarylpropynols 19a,b with 1-naphthol affords the naphthopyrans 20 together with merocyanines 21, whilst the isomeric pyrans 23 are efficiently produced from 2-naphthol. The configuration of merocyanines 7a and 21a was unequivocally established by X-ray crystallography.

LanguageEnglish
Pages1220-1230
Number of pages11
JournalEuropean Journal of Organic Chemistry
Volume2003
Issue number7
DOIs
Publication statusPublished - 1 Mar 2003
Externally publishedYes

Fingerprint

Pyrans
X ray crystallography
crystallography
synthesis
expulsion
Aluminum Oxide
constitution
Catalysis
catalysis
x rays
aluminum oxides
dyes
products
configurations
2-naphthol
merocyanine
1-naphthol
naphtho(2,1-b)pyran
2-methyl-1-naphthol
merocyanine dye

Cite this

Gabbutt, C. D., Heron, B. M., Instone, A. C., Thomas, D. A., Partington, S. M., Hursthouse, M. B., & Gelbrich, T. (2003). Observations on the synthesis of photochromic naphthopyrans. European Journal of Organic Chemistry, 2003(7), 1220-1230. https://doi.org/10.1002/ejoc.200390176
Gabbutt, Christopher D. ; Heron, B. Mark ; Instone, Alicia C. ; Thomas, David A. ; Partington, Steven M. ; Hursthouse, Michael B. ; Gelbrich, Thomas. / Observations on the synthesis of photochromic naphthopyrans. In: European Journal of Organic Chemistry. 2003 ; Vol. 2003, No. 7. pp. 1220-1230.
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Gabbutt, CD, Heron, BM, Instone, AC, Thomas, DA, Partington, SM, Hursthouse, MB & Gelbrich, T 2003, 'Observations on the synthesis of photochromic naphthopyrans', European Journal of Organic Chemistry, vol. 2003, no. 7, pp. 1220-1230. https://doi.org/10.1002/ejoc.200390176

Observations on the synthesis of photochromic naphthopyrans. / Gabbutt, Christopher D.; Heron, B. Mark; Instone, Alicia C.; Thomas, David A.; Partington, Steven M.; Hursthouse, Michael B.; Gelbrich, Thomas.

In: European Journal of Organic Chemistry, Vol. 2003, No. 7, 01.03.2003, p. 1220-1230.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Observations on the synthesis of photochromic naphthopyrans

AU - Gabbutt, Christopher D.

AU - Heron, B. Mark

AU - Instone, Alicia C.

AU - Thomas, David A.

AU - Partington, Steven M.

AU - Hursthouse, Michael B.

AU - Gelbrich, Thomas

PY - 2003/3/1

Y1 - 2003/3/1

N2 - 1-Naphthol reacts with 1,1-diarylprop-2-yn-1-ols 5a,b, under alumina catalysis, by two pathways to give the photochromic naphtho[1,2-b]pyrans 6a,b, together with the propenylidenenaphthalenones 7a,b, representatives of a new class of merocyanine dyes. With 2-methyl-1-naphthol, formation of the photochrome is suppressed; the only products are merocyanines 7c,d. The cyclocondensation of 2-naphthol with 5a,b proceeds much more efficiently, to give the naphtho[2,1-b]pyrans 14a,b. Pyran formation is not suppressed from either 1-bromo- or 1-(4 -methoxyphenyl)-2-naphthol; reaction with 5a,b merely results in expulsion of the C-1 substituent. An alternative pathway supervenes in the reaction of 1-methyl-2-naphthol with 5a to give the benz[e]indanone 17, the constitution of which was determined by X-ray crystallography. Reaction of the 1,3,3-triarylpropynols 19a,b with 1-naphthol affords the naphthopyrans 20 together with merocyanines 21, whilst the isomeric pyrans 23 are efficiently produced from 2-naphthol. The configuration of merocyanines 7a and 21a was unequivocally established by X-ray crystallography.

AB - 1-Naphthol reacts with 1,1-diarylprop-2-yn-1-ols 5a,b, under alumina catalysis, by two pathways to give the photochromic naphtho[1,2-b]pyrans 6a,b, together with the propenylidenenaphthalenones 7a,b, representatives of a new class of merocyanine dyes. With 2-methyl-1-naphthol, formation of the photochrome is suppressed; the only products are merocyanines 7c,d. The cyclocondensation of 2-naphthol with 5a,b proceeds much more efficiently, to give the naphtho[2,1-b]pyrans 14a,b. Pyran formation is not suppressed from either 1-bromo- or 1-(4 -methoxyphenyl)-2-naphthol; reaction with 5a,b merely results in expulsion of the C-1 substituent. An alternative pathway supervenes in the reaction of 1-methyl-2-naphthol with 5a to give the benz[e]indanone 17, the constitution of which was determined by X-ray crystallography. Reaction of the 1,3,3-triarylpropynols 19a,b with 1-naphthol affords the naphthopyrans 20 together with merocyanines 21, whilst the isomeric pyrans 23 are efficiently produced from 2-naphthol. The configuration of merocyanines 7a and 21a was unequivocally established by X-ray crystallography.

KW - Dyes

KW - Heterocycles

KW - Naphthopyran

KW - Photochromism

KW - Rearrangements

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U2 - 10.1002/ejoc.200390176

DO - 10.1002/ejoc.200390176

M3 - Article

VL - 2003

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EP - 1230

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T2 - Annalen der Pharmacie

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ER -