• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.218-229
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• 2011

We have involved the imine compound 1 in condensations with various nitrogenous reagents including hydrazine hydrate to construct differently substituted pyrimidines. One of the pyrimidines so obtained was further subjected to interactions with different reagents such as propionic acid, formic acid, ethyl chloroformate, acdetic anhydride, carbon disulphide, cyanogene bromide, triflauroacetic acid and ethyl chloroacetate which resulted in the formation of annulated heterocyclic systems as pairs of isomers in most cases as a result of Dimroth-type rearrangement.

• Polymer(Korea)
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• v.29 no.1
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• pp.25-31
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• 2005

Cellulose acetate derivatives containing 6-(p-hexyloxyphenyl)carbonyl spirobenzopyran (CA-COSP) were prepared from base-catalyzed etherification of cellulose acetate, and their physical and photochromic properties were characterized. The degree of substitution of COSP was calculated from the amount of residual hydroxyl groups in cellulose acetate measured by the $^1H$-NMR and UV spectrometric data. It was ranging from 0.87 to 45.5% depending on the reaction condition. UV/vis spectrometry of the resulting CA-COSP revealed that the polymer shows a reversible color change by changing its color from colorless to blue upon UV irradiation forming a merocyanine structure, and returning back again to colorless spiropyran structure by visible light or by heat. The rate of color change was faster in solution than in the film. In the more polar solvent, the more stable was the resulting merocyanine, and the slower was the rate of reverse reaction to spiropyran. Compared to COSP blended with cellulose acetate, in which a phase separation was observed for samples containing more than 0.9 wt% of COSP, up to 48 wt% of COSP could be blended in CA-COSP without phase separation.