One-pot synthesis of photochromic naphthopyrans in the solid state

Organic Letters

Volumn 2, Issue 14, 2000, Pages 2133-2134

  Tanaka, Koichi ^a   Aoki, Hiroko ^a   Hosomi, Hiroyuki ^b   Ohba, Shigeru ^b  

^a EHIME UNIVERSITY   (Japan)

^b KEIO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000875290     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol006038y     Document Type: Article

References (7)

1. Gemert, B. V. In Organic Photochromic and Thermochromic Compounds; Crano, J. C., Guglielmetti, R. J., Eds.; Plenum Press: New York, 1999.
2. Tanaka, K.; Toda, F. Chem. Rev. 2000, 100, 1025-1074.
3. Gemert, B. V.; Bergomi, M.; Knowles, D. Mol. Cryst. Liq. Cryst. 1994, 246, 67-73.
4. Typical procedure. A mixture of 1a (0.5 g, 2.4 mmol), 2 (0.34 g, 2.4 mmol), p-TsOH (0.046 g, 0.24 mmol), and silica gel (1.0 g) was ground for 10 min at room temperature using a mortar and pestle, and the mixture was kept for 1 h. The reaction mixture was chromatographed on silica gel using toluene as eluent to give 6a (0.45 g, 56% yield, mp 160-162°C) as colorless needles.
5. Knowles, D. B.; Gemert, B. V. U.S. Pat. 1995, 5,464,567.
6. 2: C, 90.06; H, 5.14. Found: C, 90.28; H, 5.24.
7. -1; 298 K. Structure refinement with TEXSAN; all H atom parameters refined; final R = 0.044 for 2995 observed reflections. Crystallographic data (without structure factors) have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-143884. Copies of the data can be obtained, free of charge, on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, U.K. (fax +44 1223 336033 or e-mail deposit@ccdc.cam.ac.uk).