Specific electron transporting molecules that can be prepared in accordance with the present invention are selected from the group consisting of anthrone derivatives and anthraquinodimethane derivatives of the following formulas: wherein A and B are independently selected from the group consisting of CN and COOR, wherein R is an alkyl group or an aryl group; X and Y are independently selected from the group consisting of alkyl, aryl, halide, hydroxy and electron withdrawing groups such as CN, NO 2 , COR, COOR, and the like, wherein R is as defined herein, and m and n are numbers of from 0 to 3.
With further reference to the process of the present invention, the condensation reaction of the anthraquinone with active methylene compounds, inclusive of malononitrile, (dicyanomethane), malonate (bis[methoxycarbonyl]methane), dinitromethane, beta diketones, and the like, is affected in a suitable organic solvent at room temperature in the presence of a base and a Lewis acid. With the proper choice of reactants, both the 11,11,12,12-tetrasubstituted anthraquinodimethane and 10-disubstituted methylene anthrone derivatives can be obtained by similar synthetic process.
More specifically, the electron transporting anthrone Pharmaceutical Intermediates derivatives are prepared by reacting 1 mole of an anthraquinone with 1 to 1.5 moles of an active methylene compound. The aforementioned condensation is affected in the presence of an excess, generally 2 to 5 moles, of a Lewis acid such as titanium tetrachloride and an excess, generally 4 to 20 moles, of a base inclusive of pyridine. Suitable solvents for the reaction include chlorinated compounds like methylene chloride, chloroform, and 1,2-dichloroethane; and ethyl acetate. Also, this reaction is usually initially accomplished at ice-bath temperatures, and then at room temperature.
Therefore, the preparation of anthrone derivatives, which can be purified by recrystallization or by chromatography, and are characterized by elemental analysis, spectroscopy and mass spectrometry, can be illustrated with reference to the following reaction scheme: wherein X, Y, Z, m and n are as defined hereinbefore.
Similarly, the electron transporting anthraquinodimethane derivatives are synthesized by reacting 1 mole of an anthraquinone with 2 to 3 moles of an active methylene compounds such as malonoitrile, malonate, and the like. The aforementioned condensation is affected in the same manner with reference to the preparation of the anthrone manufacturer derivatives except that additional Lewis acid and base are employed. Generally, thus for each mole of anthraquinone, 3 to 5 moles of titanium tetrachloride, and 6 to 25 moles of pyridine were used.
Accordingly, the preparation of anthraquinodimethane derivatives, which can be purified by simple recrystallization from a suitable solvent or by chromatography, and are characterized by elemental analysis, standard spectroscopic and mass spectrometric techniques, can be illustrated by the following reaction sequence: wherein X, Y, A, m and n are as defined herein.
With further reference to the synthesis of the anthraquinodimethane derivatives with different substituents, that is, wherein the A substituent, for example, is CN, and the B substituents are COOR, at the carbon-11 and carbon-12 position, there is reacted 10-disubstituted methylene anthrones , with 1 to 1.5 moles of active methylene compounds, in accordance with the following reaction scheme (III). The aforementioned condensation is affected in the presence of an excess, generally 2 to 5 moles of a Lewis acid such as titanium tetrachloride, and an excess, generally 4 to 20 moles, of a base inclusive of pyridine. Suitable solvents for this reaction include chlorinated compounds like methylene chloride, chloroform, and 1,2-dichloroethane; and ethylacetate. Also, this reaction is usually initially accomplished at ice bath temperatures, and then at room temperature. wherein the A substituents are COOR, the B substituents are CN, and the other substituents are as defined herein.
With regard to all the reactions illustrated herein, the reaction temperature generally ranges from about 0° to about 30° C. Electrical testing was carried out in accordance with the procedure of Example VIII. Specifically, this imaging member was positively charged to fields of 40 volts/micron and exposed to white light of wavelengths of 400 to 700 nanometers. The half decay exposure sensitivity of this device was 50 ergs/cm 2 , and its electrical properties remained substantially the same after 1,000 cycles of repeated charging and discharging.
Other modifications of the present invention may occur to those skilled in the art based upon a reading of the present disclosure and these modifications are intended to be included within the scope of the present invention.
source:townhall|anthrones
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