Reference of 873980-68-8, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 873980-68-8 as follows.
Preparation of 6-bromo-5-methybenzoxazole (43): To a suspension of 4-bromo-6-methoxy-3-methylaniline (41) (500 mg, 2.3 mmol) in 6 ml DCM was added 1 M BBr3 in DCM (4.6 ml, 4.6 mmol). The reaction mixture was stirred at r.t. for 2 h, which turned to a brown solution and back to a brown suspension. After quenched with aq. sodium bicarbonate solution, the mixture was extracted with EA. The org. phase was washed with brine, dried over sodium sulfate, concentrated to dryness to give 581 mg 2-amino-5-bromo-4-methylphenol as dark oil.A mixture of 2-amino-5-bromo-4-methylphenol (42) (290 mg), trifluoromethanesulfonic acidYtterbium (III) salt (20 mg) and trimethyl orthoformate (185 mul, 1.5 eq.) in 2 ml EtOH was heated at 90 C. for 2 h. After cooling down to r.t., the reaction mixture was taken up in EA, washed with aq. NaHCO3 and brine, dried over Na2SO4, concentrated to dryness. The resulting brown solid was dissolved in DCM and subjected to silica gel column purification using 0-60% B (A: hexane; B: 50% EA in hexane) to furnish 91.9 mg 6-bromo-5-methylbenzoxazole (43) as yellow solid (yield: 38%)
According to the analysis of related databases, 873980-68-8, the application of this compound in the production field has become more and more popular.
Reference:
Patent; CalciMedica, Inc.; US2011/263612; (2011); A1;,
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