Derivatives of 3-methyl-spiro(2h-1-betanaphthopyran-2,22h-1-benzopyran)

摘要

The invention comprises compounds of the formula FORM:0889586/IV (b)/1 and their derivatives having in the 51, 61, 71 and/or 81 positions substituents selected from CH3, CH2CH3, CH(CH3)2, C(CH3)3, C6H5, CF3, CN, COCH3, CO2C2H5, CO2H, NH2, NHCH3, N(CH3)2, N(CH3)3+, NHCOCH3, NO2, PO3H-, OCH3, OC2H5, OCH2CH2CH3, OC6H5, OH, OCOCH3, SCH3, SH, SCOCH3, SCN, SOCH3, (methyl sulphinyl), SO2CH3 (methyl sulphonyl), SO2NH2, S(CH3)2+, F, Cl, Br, I, IO2,C H2CH= CH2 and CO2CH3; these substituents are to be sterically compatible as defined below, and each substituent in each position has a definite "Ri" value (given in a Table), the substituents being selected so that the algebraic sum of the Ri values is positive. These compounds are colourless in solution, but on irradiation with electromagnetic radiation predominating in visible components the 21-11 bond is broken and the compounds are coloured; irradiation with radiation predominating in ultra-violet components reverses the process. "Sterically compatible" substituents are those which do not hinder the breaking of the 21-11 bond on irradiation. The compounds in solution can be used to sensitize record materials for the recording and erasing of data by the appropriate radiation. These compounds may be prepared by condensing the Ri-substituted salicylaldehyde with methyl ethyl ketone, condensing the product with 2-hydroxynaphthaldehyde-1, adding ethyl ether to form a precipitate, separating the ether layer, and removing the ether. An example prepares the 61-nitro derivative in this way.