One-Step Synthesis of Iodonitro Derivatives of Benzene and Diphenyl
Abstract Generated abstract
This paper addresses the preparation of iodonitro derivatives of benzene and diphenyl, noting that earlier routes required highly concentrated acids, multiple steps, or gave low yields. It proposes a one-stage synthesis based on the simultaneous action of iodine and a sulfuric, nitric acid mixture in glacial acetic acid directly on benzene or diphenyl. The procedure afforded p-iodonitrobenzene in 40% yield and 4-iodo-4′-nitrodiphenyl in 50% yield, with product identification supported by melting points and qualitative tests for iodine and nitrogen.
Full Text
ONE-STAGE SYNTHESIS OF IODONITRO DERIVATIVES OF BENZENE AND DIPHENYL
A. N. NOVIKOV, A. M. SEDOV
(Presented by the scientific-methodological seminar of the KhTF)
It is known from the literature that p-iodonitrobenzene can be synthesized by various methods. It has been obtained by the action of fuming H₂SO₄ and nitrogen oxides on iodobenzene [1]; from p-nitroaniline by diazotization followed by treatment with potassium iodide [2].
4-Iodo-4′-nitrodiphenyl was prepared from diphenyl by a multistage synthesis involving nitration, reduction, diazotization, and subsequent replacement of the diazo group by iodine [3].
The disadvantages of these methods are the use of acids of high concentration, the multistage nature of the procedures, and the insignificant yields of iodonitro products.
The present work reports the results of a search for one-stage methods for obtaining p-iodonitrobenzene and 4-iodo-4′-nitrodiphenyl. The proposed method is based on the simultaneous action of iodine and a sulfuric–nitric acid mixture on benzene and diphenyl.
Experimental Part
Synthesis of p-iodonitrobenzene.
Into a round-bottomed three-necked flask were charged 8.9 ml of benzene, 12.7 g of finely powdered iodine, and 20 ml of glacial acetic acid. At a temperature of 110°C (the temperature of the glycerin bath), a sulfuric–nitric acid mixture consisting of 12.2 ml of nitric acid, $d$ 1.4, and 27 ml of sulfuric acid, $d$ 1.83–1.84, was added dropwise over 1 hour. After addition of the sulfuric–nitric acid mixture, stirring was continued for another 0.6 hour. The reaction mass was then diluted with water; the precipitated solid was filtered off, washed with water, dried, and recrystallized from benzene. Yield of p-iodonitrobenzene: 9.9 g (40%). $T_{\text{m}} = 171^\circ$C. The qualitative reaction for iodine and nitrogen was positive.
Synthesis of 4-iodo-4′-nitrodiphenyl.
15.4 g of diphenyl, 12.7 g of finely powdered iodine, and 50 ml of glacial acetic acid were placed in a flask. At a temperature of 80°C and with mechanical stirring, a mixture of 10.8 ml of nitric acid, $d$ 1.4, and 27 ml of sulfuric acid, $d$ 1.83–1.84, was gradually added to the flask over 1.5 hours. After addition of the nitrating mixture, the synthesis was completed after 0.5 hour. The reaction mass was then diluted with water; the precipitate was filtered off, washed with water, and recrystallized from toluene. Yield of 4-iodo-4′-nitrodiphenyl: 16.2 g (50%). $T_{\text{m}} = 211–212^\circ$C. The qualitative reaction for iodine and nitrogen was positive.
Conclusions
In one stage, p-iodonitrobenzene was obtained in 40% yield and 4-iodo-4′-nitrodiphenyl in 50% yield by the action of iodine and a sulfuric–nitric acid mixture (nitric acid \(d\ 1.4\), sulfuric acid \(d\ 1.83\text{–}1.84\)) directly on benzene and diphenyl.
Literature
- R. L. Datta, P. S. Varma. J. Am. Chem. Soc., 41, 2047 (1919).
- Montagne. Ber., 51, 1489 (1918).
- R. Belcher et al. J. Chem. Soc., 1334 (1953).