17724-14-0Relevant articles and documents
4 - [6 - (methylthio) benzo [1,2-d:5,4-d '] b [1,3] oxazole-2-yl] benzoic acid and its preparation method
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Paragraph 0017-0020, (2017/02/28)
The invention discloses 4-[6-(methylthio) benzo [1, 2-d: 5, 4-d']-di-[1, 3] oxaxole-2-yl] benzoic acid and a preparation method thereof. The preparation method comprises the steps as follows: resorcinol is taken as a raw material and subjected to sulfonation, nitration, hydrolysis and reduction to obtain 4-amino-6-nitroresorcinol hydrochloride; ANR*HCl and p-methoxycarbonyl benzoyl chloride (MBC) are subjected to condensation, cyclization and dehydration to obtain 4-(6-hydroxy-5-nitrobenzo[d]oxazole-2-yl) methyl benzoate; NHABE is subjected to hydrogenation reduction under the action of a Pd/C catalyst to obtain 4-(6-hydroxy-5-aminobenzo[d]oxazole-2-yl) methyl benzoate; AHABE and CS2 are subjected to cyclization under the alkaline condition to obtain 4-(6-(mercapto)benzo[1, 2-d:5, 4-d']-di-(oxazole)-2-yl) benzoic acid; and dimethyl methyl sulfate is compounded to the target compound 4-[6-(methylthio) benzo [1, 2-d: 5, 4-d']-di-[1, 3] oxaxole-2-yl] benzoic acid. According to the invention, a novel compound is obtained, the method is simple and convenient, and the product yield is high.
Sulfonation and sulfation of 1,3-dihydroxybenzene and its methyl ethers in concentrated sulfuric acid
Cerfontain, Hans,Koeberg-Telder, Ankie
, p. 543 - 548 (2007/10/02)
The homogeneous sulfonations of 1,3-dihydroxybenzene (1), its monomethyl (2) and dimethyl ether (3) in concentrated aqueous sulfuric acid at 25 deg C have been studied and isomer distributions and rate coefficients for the sulfonation of 1-3 and their monosulfonic acids are reported.The initial process, upon dissolution of the reactants, is protonation at C(4) and C(6).The subsequent sulfonation of the symmetrical reactants 1 and 3 yields the 4-sulfonic acids and that of 2 the 4- and 6-sulfonic acids, the ratio of which is 0.8 +/- 0.1 at 73.5percent H2SO4.The sulfonation of the 4-sulfonic acid of 1 (1-4-S) yields a mixture of 2,4- and 4,6-disulfonic acids, that of 2-4-S and 3-4-S yields the 4,6-S2 and that of 2-6-S gives a mixture of 2,6- and 4,6-S2.The disulfonic acids 1-2,4-S2 and 2-2,6-S2 both slowly isomerize to yield the 4,6-disulfonic acid isomers.At acid concentrations >= 82.2percent H2SO4, the disulfonic acids of 1 slowly yield 1-2,4,6-S3, whereas those of 2 and 3 are not further sulfonated.The absence of 2-2,4-S2 from 2-4-S and of 2-2,4,6-S3 is discussed in terms of conformer populations of the precursory sulfonic acid substrates.
