Reaction of 1-amino-2-phenylethynyl-and 2-acylethynyl-1-amino-9,10-anthraquinones with HNO2. Synthesis of 1H-3-acylnaphtho[2,3-g]indazole-6,11-diones
                                
                                    
                                        作者:I. D. Ivanchikova、L. G. Fedenok、M. S. Shvartsberg                                    
                                    
                                        DOI:10.1007/bf02495357
                                    
                                    
                                        日期:1997.1
                                    
                                    The reactions of 1-amino-2-phenylethynyl- and 2-acylethynyl-1-amino-9,10-anthraquinones with HNO2 in a mixture of dioxane and a mineral acid at 20 degrees C were studied. Under these conditions, 2-alkynyl-1-amino-9,10-anthraquinones, irrespective of the structure of the C=CR substituent, are cyclized into 3-substituted 1H-naphtho[2,3-g]indazole-6,11-diones. The nature of the acetylenic group in the initial compound and the choice of the mineral acid determine the structure of the substituent in position 3 of the product (1,1-dichloroalkyl or acyl) but have no effect on the regiospecificity of cyclization.