2-Amino-4-methyl-5-phenylazo

Thiazol 2-Amino-4-methyl-5-phenylazo- E16d, 40 (Azokupp-lung)... 

Reaction of 2-amino-3-phenylazo-5-methyl-6,7-dihydropyrazolo [ 1,5-a] -pyrimidine-7-one (209) with ACOH/H2SO4 gives the pyrazolo[l,5-a]-pyrimidine derivative 210 (77JHC155). This reaction can be looked at as electrophilic substitution of the arylazo function by the proton. Similarly, 4,5,6,7-tetrahydro-2-phenyl-3-phenylazo-5-oxopyrazolo[l,5-a] pyrimidine gives 4,5,6,7-tetrahydro-2-phenyl-5-oxopyrazolo[l,5-a]pyrimidine 212 by the action of acetic/hydrochloric acid (75T63). 

Methyl-2-(4-inethyl-phenyl)-4-phenyl-2,4-dihydro- (r = CHj-c H.,)178 Ei-a-25i4 2,91 g (0,01 mo ) 5-Amino-3-methyi-4-(4-methyl-phenylazo)-l-phcnyl-1 H-pyrazol werden in 10 m/ DMF mit 1 g (0,0052 mol) Kupfer(II)-acctat 1 h auf 90-95° erhitzt, dabei wird ein Luftstrom durch... 

Amino-lH-indazol gibt mit Benzoldiazoniumchlorid 6-Amino-7-phenylazo-lH-indazol254 [braungelbe Nadeln Schmp. 1641 (Methanol)], 6-Amino-l-methyl-2H-indazol 3 [Pg.822]

Amino-4-phenyl- 224 2-Amino-5-phenylazo-4-(2-thicnyl)- 64 2-(2-Amino-phenyl)-4-(4-chlor-phenyl)- 199 2-Amino-4-(2-phenyl-cyclopropyl)- 49 2-Amino-4-(2-phenyl-ethyl)- 90, 94, 223 4-(4-Amino-pheny1)-2-methyl- 30... 

Reactions of 5f/-2-methyl-l,2,4-triazepino[2,3- ]benzimidazol-4-one 71, prepared by reaction of 1,2-diaminobenz-imidazole 72 with acetoacetic ester 73, with different reagents was described, in the search of new heterocycles with biological activity <2002CHE598>. When lactam 71 was treated with aromatic aldehydes in boiling 1-BuOH with addition of piperidine 74, 577-3-arylidene-2-methyl-l,2,4-triazepino[2,3- ]benzimidazol-4-ones 75a-c were obtained (Scheme 7). Coupling lactam 71 with phenyldiazonium chloride 76 in dioxane afforded the 3-phenylazo-substituted tricycle 77. When 71 was treated with phosphorus pentasulfide 78 in boiling dioxane or pyridine, its thio analog 79 was obtained. The reaction proceeded most efficiently when lactam 71 was refluxed with twofold excess of 78 in dry dioxane. These thiones 79 react with ammonia and amines by nucleophilic substitution. When 79 was refluxed with ammonia, benzylamine, piperidine, or morpholine, the 4-amino-substituted tricycles 80a-d were obtained. All the described compounds were identified by NMR, mass spectrometry, and IR spectroscopy. 

It is interesting to note that azo compounds may be conveniently reduced either by a solution of tin(n) chloride in hydrochloric acid or by sodium di-thionite. Thus l-phenylazo-2-naphthol yields both aniline and l-amino-2-naphthol, and methyl orange gives p-amino-Af,Af-dimethylaniline and sulphanilic acid. 

Heating 9-hydroxy-2-methyl-8-nitro-4//-pyrido[ 1,2-a]pyrimidin-4-one 326 in dimethylformamide in the presence of hydrazine hydrate and Raney nickel at 50°C afforded 8-amino derivative 327 (92KGS1660). 8-Amino derivative 327 was also prepared from 8-phenylazo derivative 328. 

An early unequivocal synthesis of (11) which, however, is too involved to be practical, involved condensation of 2-amino-4-chloro-5-phenyIazo-6-hydroxy-pyrimidine with the ethylene ketal of aminoacetone, followed by reduction of the phenylazo group, hydrolysis and cyclization to 6-methyl-7,8-dihydropterin. This latter intermediate was then oxidized with potassium permanganate to 6-methylpterin, which was converted to (11) with selenium dioxide in acetic acid (63% in the last step) [36] (Scheme 3.1). 

Thiazol 2-Amino-5-(4-aminosul-fonyl-phenylazo)-4-methyl- E16d, 40 (Azokupplung)... 

Amino-ethyl)-l-methyl- E6b/1, 483 (Lactam-Red. C,N-Spalt.) 2-(3-Amino-propyl)- E6b/1, 483 (Lactam-Red. C,N-Spalt.) Methan (4-Butyl-phenyl)-diazo-E14b, 1003 (Hydrazon-Ox.) 2-Penten 3-Phenylazo- E15/1. 967 (Hydrazon + Py)... 

Pyrazin 2-(bzw. 4)-(4-Methyl-anilinocarbonyl)- E5, 1017 (N3 -v CO-NH-Ar) Pyridazine 4-Cyan-6-hydroxy-5-methyl-3-phenyl-4,5-dihydro-E9a, 570 (4-Oxo -4-Ar-3-CN-2-CH3 —butanoic Acid + N2H4) Pyridin 2-Methoxy-5-phenylazo-E16d, 57 (R-NH2 + R-NO) Pyrrol 2-Amino-3-cyan-1 -(4-methyl-phenyl)- 5-oxo-4,5-dihydro-E15/2, 1946 (Cl-CH2-CO-NR2 + NC-CH2-CN) Quinolin... 

Amino-5-methyl- 815 6-Amino-l-methyl-7-phenylazo- 822 l-Amino-5-nitro- 822 3-(2-Amino-phenyl)- 847... 

IT25, Calmagite, 3-Hydroxy-4-[(2-hydroxy-5-methyl-fhasltaio]-l-naphthalenesulfonic acid 1 -(1 -hydroxy-4- Uhyl-2-phenylazo)-2 - n aph thol -4 -sulf onic acid. C,H 4-NftS mol wt 358.38. C 56.97%, H 3.94%, N 7.82%, O B.32%, S 895%. Prepn from I -amino-2-naphthol-4-sul-loik acid and p-cresol Lindstrom, Diehl, Anal. Chem. 32, 1123(1960). 

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