反应详情

温度

-10 °C

3,4,5-Triiodoaniline was obtained by the procedure of L. Kalb (L. Kalb et al., Über substituierte Indol-2-carbonsäure-8-propionsäuren and einige jodierte Bensolderivate, Chem. Ber. 59 (1926) 1860-1870). 4 g (8.5 mmol) of 3,4,5-triiodoaniline were stirred with the solution of 2.3 mL of concentrated hydrochloric acid and 2.3 mL of water. The mixture was cooled to about −10° C. and the equivalent quantity of 2.5 M solution of NaNO2 was added dropwise with intensive stirring. The reaction mixture was continued stirring for 30 min at −10° C. Next, the cooled solution of 5.75 g (25.5 mmol) of SnCl2-2H2O in 6 mL of concentrated HCl was added dropwise at −10° C. to the suspension of diazocompound. The reaction mixture was kept at −10° C. for one hour and at 5° C. overnight. The obtained precipitate was filtered off and washed with water to yield 4.7 g of 3,4,5-triiodophenylhydrazine, as a double salt with tin chloride, which was used for following step without additional treatment or purification. 1H-NMR (200 MHz, DMSO-d6), δ, ppm: 10.14 (2H, broad s, NH2), 8.46 (1H, s, NH), 7.5 (2H., s, arom.).

1. waitThe reaction mixture was kept at −10° C. for one hour and at 5° C. overnight
2. filtrationThe obtained precipitate was filtered off
3. washwashed with water