Methanol → 4-(3,5-dinitrothien-2-ylazo)-N-ethyl-N-(4-fluorosulphonylphenyl)propyl aniline

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Reaction Steps

2-Amino-3,5-dinitrothiophene (0.01 mol) was dispersed in a mixture of acetic:propionic acid (86:14; 25 cm3), cooled to 0°-5° C. and nitrosyl sulphuric acid (0.01 mol) added portionwise at 0°-5° C. The reaction mixture was stirred for 10 minutes at 0°-5° C. then added dropwise to a mixture of the N-ethyl-N-(4-fluorosulphonylphenylpropyl)aniline (0.01 mol), methanol (50 cm3) and ice (50 g). The resultant precipitate was filtered washed with water and then methanol and oven dried at 50° C. The dry dye has a λmax of 617 nm and gives good fastness to washing, light and heat.

Provenance & Evidence