Patent ID: 6891067
Filing Date: 2005-05-10
Classification: C07C,C07D,C08G,G02B

Abstract:
1. A method of preparing a diamine compound for use as an optical polyimide precursor, comprising the steps of: dissolving 2-chloro-5-nitrobenzotrifluoride and a diol in N,N-dimethylacetamide to form a solution; adding potassium carbonate, tert-butylammonium chloride and copper powder to said solution and heating the resulting mixture; removing the copper; precipitating and recrystallizing a dinitro-compound resulting from heating the mixture; and dissolving the dinitro-compound and reducing the dinitro-compound to yield said diamine compound having the formula: where A represents a divalent aromatic moiety and X is selected from the group consisting of Cl, Br and fully halogenated alkyl.