Patent ID: 6737548
Filing Date: 2004-05-18
Classification: C07C

Abstract:
A process for preparing a 1,5-diaminonaphthalene derivative comprising:(i) the first step comprising reacting an ortho-alkylnitrobenzene represented by formula (1): wherein R1 to R4, which may be the same or different, represent hydrogen, alkyl having 1 to 4 carbon atoms, aromatic hydrocarbon having 6 to 12 carbon atoms, or halogen; and R5 represents hydrogen, with a vinyl compound represented by formula (2): wherein R6 and R7, which may be the same or different, represent hydrogen, alkyl having 1 to 4 carbon atoms, or halogen; and X represents an electron withdrawing group, provided that R6 and R7 are mutually cis- or trans-configured, in the presence of a base, to produce an aromatic nitro compound represented by formula (3): wherein R1 to R7 are as defined in formulas (1) and (2); and X represents an electron withdrawing group, which may be the same as or different from X as defined in formula (2);(ii) the second step of cyclizing the aromatic nitro compound represented by formula (3) to produce a 5-nitro-1-tetralone derivative represented by formula (4): wherein R1 to R4 and R6 to R7 are as defined in formulas (1) and (2); and(iii) the third step comprising reacting the 5-nitro-1-tetralone derivative represented by formula (4) with an amine to provide an intermediate, which is then reduced and aromatized to produce the 1,5-diaminonaphthalene derivative represented by formula (5): wherein R1 to R4 and R6 to R7 are as defined in formulas (1) and (2).