Griffith, R. H.; Hope, Edward published an article in 1925, the title of the article was Synthesis of 5,5′-dibromo-6,6′-dimethoxy-2,2′-bisoxythionaphthene.HPLC of Formula: 152626-77-2 And the article contains the following content:
5-Bromo-2-acetylamino-p-tolyl Me ether (I), m. 191°; hydrolysis with concentrated HCl gives the amine, m. 100° (Bz derivative, m. 159°); the azo dye with β-C10H7OH, red needles with green luster, m. 210°. Diazotized and reduced with SnCl4, the amine gives a hydrazine, pale brown, m. 192°, which, on treatment with CuSO4 and oxidation with alk. KMnO4, yields 3-bromoanisic acid, m. 217-8°. Since the 2-Br derivative is recorded as m. 212°, it was synthesized from 2-bromo-p-tolyl Me ether, b16 114° b760 222°, and found to m. 199°. Oxidation of I with KMnO4 in the presence of MgSO4 gives about 70% of 5-bromo-2-acetylamino-4-methoxybenzoic acid, m. 253°; hydrolysis with concentrated HCl gives 4-bromo-m-anisidine, m. 90.5° (Bz derivative m. 124°); hydrolysis with alkali gives 5-bromo-2-amino-4-methoxy-benzoic acid, pale brown, m. 201°, decomposed 213° (Na salt, long needles; Cu salt, green). Diazotized, treated with Na2S2 and boiled with Zn dust in Na2CO3 solution, it yields 5-bromo-4-methoxy-2-thiolbenzoic acid, which, because of its ease of oxidation, is used as the Na salt in the condensation with ClCH2CO2H, forming 4-bromo-2-carboxy-5-methoxy-phenylthiolacetic acid (II), pale brown, m. 243° (decomposition). Heated with AcONa and Ac2O, dissolved in 3% alkali and treated with K3Fe(CN)6, it gives 5,5′-dibromo-6,6′-dimethoxy-2,2′-bisoxythionaphthene (III), dark red, m. 355-60°; the dye is reprecipitated from its deep blue solution in concentrated H2SO4 in a gelatinous state very suitable for the preparation of the vat, which is pale yellow and dyes cloth a good scarlet. The PhNO2 solution shows an absorption band with a maximum at λ = 529; “Helindone Fast Scarlet R” shows a similar band with a maximum at λ = 520. II and isatin give the compound C17H10O3N-BrS (IV), which has a much bluer shade than III; its H2SO4 solution is purple but its dyeing properties are unsatisfactory, probably on account of further reaction during reduction. II and acenaphthenequinone give an orange powder (V), m. 337°, giving dark brown solutions in concentrated H2SO4 and dyeing cloth a good orange from a bright blue bath. The experimental process involved the reaction of 4-Bromo-5-methoxy-2-methylaniline(cas: 152626-77-2).HPLC of Formula: 152626-77-2
4-Bromo-5-methoxy-2-methylaniline(cas:152626-77-2) belongs to ethers. Oxygen is more electronegative than carbon, thus the alpha hydrogens of ethers are more acidic than those of simple hydrocarbons. They are far less acidic than alpha hydrogens of carbonyl groups (such as in ketones or aldehydes), however. HPLC of Formula: 152626-77-2
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem