Effect of Temperature on the Reaction of 2-( N-acetylamine )-3-( 3 , 5-di-tert-butyl-4-hydroxyphenyl )-propionic Acid with Oxygen in an Alkaline Condition

Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55 ̊C 60 ̊C, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95 ̊C 97 ̊C, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.

The direction of oxidation by oxygen 4-replaced 2,6-di-tert-butylphenols depends on conditions and a constitution of substituent and in each specific case results, as a rule, are ambiguous [6].

Experimental Part
NMR spectrums registered on the device "Avance-500 Bruker" rather TMS.
From the data of the spectrum 1 Н NMR follows that signals of 6.69 and 6.95 ppm (J = 2.9 Hz) to belong to two various protons in a hexatomic cycle of structure 2. In the spectrum 13 С NMR signals of 138.92 and 139.59 ppm from atoms of carboneum correspond to the data, which analysis in a format debt (Figure 2) specifies in communication of these atoms with hydrogen.
Signal of 185.4 ppm in spectrum 13 C NMR (Figure 3) confirms presence of a carbonyl group at a hexatomic cycle of structure 2. Figure 1.Spectrum 1 H NMR of reactionary mass of reaction compound 1 with oxygen in an alkaline condition at 55˚C -60˚C for 6 h.At last, a signal of 76.28 ppm belongs to tetrahedral atom of carboneum, forming communications with cycle carboneums atom, tert-butyl group and atom of oxygen (Figure 4).
According to [9], a position of a signal from tetrahedral atom of carboneum in spiran to system with atom of nitrogen is in area of 75 ppm.
Data of spectrums NMR is sufficient for conclusions about structure of compound, producing by a interaction of 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid wih O 2 at temperature of 50˚C -60˚C in solution of ethanol.This fact confirms bonding between atom of oxygen of a carboxyl group and of carboneum atom from hexatomic cycle.
The interrelation of resultants of reaction (2 and 4) are found from comparison there of integrals signals in spectrum 1 H NMR reactionary mass (Figure 5 and Figure 6).
The analysis of dates of a spectrum specifies in presence at reactionary mass of three compounds are identified: one of them is with structure 2 and two compounds are with structure 4 which, apparently, are structure of isomers (Figure 6).
Signals "doublet of doublets" belong to one of structure 4а, the signal "triplet" belongs to 4b (Scheme 3).

Figure 2 .
Figure 2. Fragment of the spectrum 13 С NMR compound 2 in a format dept.

Figure 3 .
Figure 3. Spectrum 13 C NMR from reactionary mass of compound 1 with oxygen in an alkaline condition at 55˚C -60˚C for 6 h.

Figure 5 .
Figure 5. Spectrum 1 Н NMR reactionary mass after oxidation of compound 1 by oxygen at 95˚C -97˚C for 6 h.