... chemistry.” Moscow, “Mir,” 342, 1967.
3. H. Y. Chen, L. E. Hakka, R. L. Minman, A. J. Kresge, B. B. Whipple, J. Am. Chem. Soc., 93, 5102, 1971.
4. V. F. Traven’, V. A. Smrchek, B. I. Stepanova. KhGS, 568, 1967.

REARRANGEMENT OF N-ACETYLDIPHENYLAMINE

E. E. Sirotkina, R. M. Kogan

The Fries–Rosemund rearrangement, as a convenient preparative method for the synthesis of aliphatic–aromatic ketones as applied to diarylamine derivatives, has not given positive results. In the rearrangement of N-substituted diarylamines, the ortho derivatives formed either cyclize to the corresponding acridines /1/ or, as in the case of N-acetyldiphenylamine, rearrangement does not take place even in the presence of such active catalysts as aluminum chloride and polyphosphoric acid /2, 3/.

We have studied the rearrangement of N-acetyldiphenylamine in the presence of equimolecular amounts of aluminum chloride and hydrogen chloride in various organic solvents at different temperatures and reaction times. In all the cases investigated, an intermolecular rearrangement is observed with formation of diacetyldiphenylamine and diphenylamine. Among the solvents studied (nitrobenzene, nitromethane, chlorobenzene, methylene chloride), the last proved to be the best; the highest yield of diacetyldiphenylamine (30% of theoretical) is attained in 30 min of reaction time at a temperature of 40–41°C. With an increase in the duration of the reaction, resinification of the products increases.

To elucidate the donor activity of the heteroatoms of acetyl derivatives of diphenylamine, the IR spectra of complexes of N-acetyldiphenylamine and diacetyldiphenylamine with aluminum chloride were investigated. In the spectra of the complexes, new absorption bands appear in the regions 1400–1700 cm$^{-1}$ and 2900–3100 cm$^{-1}$, indicating that both onium centers participate in complex formation. When hydrogen chloride is added to the system, the intensity of the absorption band of the bound C=O group (1572 cm$^{-1}$) increases and the intensity of the absorption bands of the tre-

of the amide group (1200–1400 cm\(^{-1}\)), which is in good agreement with the ability of diphenylamine derivatives to form compounds of the ammonium-salt type with strong acids. Salt formation at this nitrogen atom apparently leads to weakening of the C–N bond, as a result of which rearrangement of the acyl group from the \(N\)-position into the aromatic nucleus occurs. In the absence of such a salt, no rearrangement is observed /2, 3/.

Experimental Part

Into a round-bottom flask equipped with a stirrer, a dropping funnel, a reflux condenser, and connected to an apparatus for generating gaseous hydrogen chloride were placed 5.025 g (0.025 M) of \(N\)-acetyldiphenylamine (mp 101°C), 20 ml of methylene chloride, and gaseous hydrogen chloride was passed through for 20 minutes. The hydrochloride salt of \(N\)-acetyldiphenylamine precipitated. After addition of a catalyst suspension (3.32 g of aluminum chloride in 10 ml of solvent), the reaction mixture was kept for 30 minutes at 40–41°C and then poured into ice water. The crystals that separated were filtered off, washed with water to neutral reaction, and dried in air.

The reaction products were separated by preparative thin-layer chromatography /4/ on a 1 cm layer of silica gel (KSK) in the solvent system isopropyl alcohol–benzene (1:6). 1.87 g of diacetyldiphenylamine was isolated (30% of theoretical). Analyses: mp 87–88°C (one recrystallization from alcohol), molecular weight 250 (calculated 253), \(N\) % 5.4 (calculated 5.53), total content of \(N\)-acetyl groups (by hydrolytic cleavage /5/), 33.0% (calculated 33.9), number of \(N\)-acetyl groups (by hydrolytic oxidation /5/) 16.4% (calculated 16.9). IR spectra (IKS-14) of diacetyldiphenylamine indicate the presence of C=O (1674 cm\(^{-1}\)), C–N< (1300 cm\(^{-1}\)), and a 1,2-substituted benzene ring (1038–1080 cm\(^{-1}\), 692 cm\(^{-1}\)); consequently, the acetyl groups are located: one at the atom, the other in the ortho position of the aromatic nucleus.

Literature

1. A. E. Porai-Koshits. Selected Works. Publishing House of the Academy of Sciences of the USSR, 1949.
2. B. I. Ardashev, V. I. Minkin. Advances in Chemistry, 28, 2, 1959.

1. Birchall J. M., Phorpe D. H., J. Chem. Soc., 2898 (1966).

2. A. A. Akhrem, A. M. Kuznetsova. Thin-Layer Chromatography. Moscow–Leningrad, “Nauka,” 1965.

3. Houben–Weyl. Methods of Organic Chemistry. Moscow, “Nauka,” 1963.

INTERACTION OF 4-OXYDIPHENYLAMINE WITH VINYL ACETATE

E. E. Sirotkina, R. M. Kogan

The study of the interaction of vinyl ethers with aromatic compounds that contain two active groups—hydroxyl and amino—is of interest for the preparation of vinyl monomers and polymers. When aromatic amino alcohols with a hydroxyl group in the side chain were used, cyclic adducts /1/ were synthesized in good yield instead of the expected alkenyl ethers. Vinyl ethers of aminophenols and oxydiphenylamines obtained by Reppe vinylation have been described, and only the hydroxyl group proved to be reactive /2/.

In the present work the behavior of 4-oxydiphenylamine in a vinyl-exchange reaction with vinyl acetate in the presence of mercury salts and sulfuric acid was studied. The amount of amino groups that had reacted was determined by the nitrosation method /3/; the conversion of oxy groups was calculated as the difference between the total conversion of vinyl acetate and the amount of amino groups that had reacted.

As is seen from the data given in Table 1, the rate of interaction of the \(>NH\) and \(-OH\) groups depends on the ratio of the initial reagents, with the amino group being the most active. The \(N\)-vinyl group under the reaction conditions polymerizes immediately, whereas the vinyloxy group undergoes no further transformations.

Introduction of an electron-donor oxy group into the para position leads to a redistribution of the electron density in the amine molecule /4/, which is accompanied by an increase in the negative charge on the nitrogen atom. This apparently explains the preferential pervinylation of 4-oxydiphenylamine at the amino group.

At an amine:vinyl acetate ratio of 1:1, the reaction products are \(N\)-vinyl oligomers containing unsubstituted oxy groups; with an excess of vinyl acetate relative to