Wohl, A. published the artcileBromination of unsaturated compounds with N-bromoacetamide, a contribution to the study of the course of chemical processes, Computed Properties of 594-81-0, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1919), 51-63, database is CAplus.
It has now become quite widely accepted that substitution reactions are often preceded by addition reactions and the present investigation was carried out in the course of a search for reactions which would make it possible to decide with certainty whether there is really a primary addition and, if so, whether it is molecular or atomic. W. found, e. g., that the reaction Me2C:CMe2 + AcNHBr (a) → Me2C:CMeCH2Br + AcNH2 occurs under such conditions (good cooling in Et2O or Me2CO) that the (a) is not dissociated at all or only to a very minute extent; no HBr can be detected. This reaction can in no way be explained as taking place by addition of the residues Br and AcNH of the (a) to the two C atoms of the double bond, for an acetylated bromoamine would split off HBr and not AcNH2. Moreover, the behavior of (a) towards Me2C:CHMe (see below) also shows that the Br does not combine with either of the unsaturated C atoms. There, therefore, remains but one possibility, that the primary addition occurs through subsidiary valences on (a) and one or both of the trivalent C atoms and the resulting unstable structure with the loosest union between Br and N then loses AcNH, forming AcNH2 with the most labile H atom after the Br and this H atom, obeying the law of neutralization, have exchanged places. According to W.’s views, the high additive power of (a) depends on the union, the spatial proximity, of the two fields of affinity of the unsaturated negative atoms -NBr, just like H2N.OH, H2N.NH2, HO.NO, (HO)2SO, HN:C, etc. Compounds without this union, like the hydrazonium salts, H2NNMe3I, are quite indifferent, e. g., towards aldehydes. Me2C:CHMe and (a) under such conditions (sufficient dilution and cooling) that AcNH2 seps. and the Br derivative remains in solution give exclusively a di-Br compound C5H8Br2. If, however, equimol. amounts of Me2C:CHMe and (a) are brought together in cold Et2O they combine and sep. practically quant. as an oil which, when the Et2O is poured off, undergoes an energetic reaction just like when Me2C:CHMe and (a) are brought together without a diluent. It is, therefore, not the addition product stable at low temperatures which determines the course of the substitution reaction but some part of it (which could not be isolated) in the mixture formed when the temperature is raised. In the substitution reaction it is one of the primary H atoms, not the tertiary atom, which is replaced. The primary addition is, therefore, determined by the coóperation of the Br-N secondary valences and the C double bond, and the further course of the reaction by the mobility of the H atoms; according to the well-known rule, the double bond loosens the H on the adjacent C atom. In harmony with these views it was found that (a) does not attack compounds saturated in the usual sense (except Me3CBr) and a series of compounds unsaturated in the ordinary sense but lacking the conditions of easy addition or of mobile H atoms (EtBr, iso-PrBr, (CH2Br)2, PhCH2Br and CH2(CO2Et)2 in the first group and C2H4, C2H2, maleic and fumaric acids, PhCH:CHCO2H, PhCH:CHCO2Et and PhCH:CHCHO in the second group). Malonic ester, in spite of the mobile H atoms, lacks a grouping appropriate for the primary addition; this, however, is present in the derivative EtO2CCH2CONH2 which in Me3CO smoothly forms the compound EtO2CCHBrCONH2, the transient yellow color appearing during the course of its preparation indicating the formation of a Br-N compound with pentavalent N in which the migration of the Br from N to C occurs by intramol. substitution. The indifference of the other compounds of the second group is easily explained by the absence of a reactively influenced H atom. On the other hand, AcCH2CO2Et, PhOH and, to a less marked degree, PhOMe react with (a) just like Me2C:CMe2 and Me2C:CHMe. The same is true of Me3CBr, PhCH:CH2, MeCH:CHCO2H, NCCH2CO2Et, AcH, HCO2H and HCO2Et. The (a) used was recrystallized from C6H6, m. 108° and was colorless; as diluents were used Et2O (in which it is not soluble but dissolves as the reaction proceeds and AcNH2 seps.) or Me2CO which dissolves (a) readily without being itself markedly brominated in the cold. In general, as soon as the starch-iodide reaction was no longer given, the AcNH2, was removed, after addition of Et2O, by shaking with Na2CO3 and washing with H2O and the H2O-insoluble layer was dried with Na2SO4 and fractionated in vacuo. Without a diluent (a) acts on easily brominated compounds with much evolution of heat, darkening and violent decomposition, the unattacked (a) itself being thereby decomposed with liberation of Br. From 10 g. cold Me2C:CHMe treated with four 10-g. portions of (a) in 60 cc. Me2CO was obtained 9 g. of a compound, C5H8Br2 (b) (found 69.74% Br; calculated, 70.14), b12 54-5°, decolorizes KMnO4 and Br-H2O in alc.; no mono-Br derivative is formed, even when a large excess of Me2C:CHMe is used (20 g. to 20 of Br). Me2C:CBrMe, prepared by Bauer’s method (Bull. soc. chim. 2, 149(1860)) but from pure Me2C:CHMe instead of amylene, b766 119-20°; it reacts much more slowly than Me2C:CHMe with (a); 14.9 g. added at room temperature to 13.8 g. (a) in 60 cc. Me2CO and allowed to stand 24 hrs. without cooling, gave, besides unchanged Me2C:CBrMe, a fraction b25 96-8° with 69.43% Br. This dibromotrimethylethylene partly polymerizes on cooling and unlike (b) has an intense odor and attacks the eyes. From 10 g. Me2C:CMe2 in 36 cc. cold Et2O and 16 g. (a) is obtained about 3 g. of not quite pure bromotetramethylethylene (found 46.3% Br; calculated 49.0%), b15, 60-90°, decolorizes KMnO4, easily decomposes and polymerizes. Me3CBr (37 g.) in 10 cc. cold Et2O slowly treated with 37 g. (a) yields 7 g. Me2C(CH2Br)Br, b36 60-1°, b. 149°. From 44.3 g. PhOH in 145 cc. cold Et2O treated at 12 hr. intervals With, 20, 20 and 25 g. (a) is obtained p-BrC6H4OH, m. 64°, b21 1.39°, b, 236°. PhOMe (10.8 g.) and 13.8 g. (a) in 65 cc. Me2CO after 24 hrs. at room temperature gave 17 g. p-BrC6H4OMe, m. 11-1.5°, b. 215°. AcCH2CO2Et (21.7 g.) in 100 cc. cold Et2O treated in the course of 1 day with 8 + 8 + 7 g. (a) yields 15 g. AcCHBrCO2Et, b18 106-8°. From 2 g. EtO2CCH2CONH2 (prepared by heating EtO2CCH2C(OEt):NH.HCl at 125-30°) in 5 cc. cold Me2CO, slowly treated with 2 g. (a) in 5 cc. Me2CO and allowed to stand 24 hrs. to disappearance of the yellow color and the starch-iodide reaction, is obtained a mixture of AcNH2 and EtO2CCHBrCONH2
Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C19H24BNO2, Computed Properties of 594-81-0.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary