Related Products of 18595-18-1,Some common heterocyclic compound, 18595-18-1, name is Methyl 3-amino-4-methylbenzoate, molecular formula is C9H11NO2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
In a 500-ml three-necked flask with mechanical stirrer, 20 g (121 mmol) of 3-amino-4-methylbenzoic acid methyl ester, 17.14 g ammonium tetrafluoroborate and 217 ml water are cooled to 0 C. and then 24.6 ml concentrated hydrochloric acid is added dropwise. Then a solution of 8.35 g (121.1 mmol) of sodium nitrite in 21.7 ml water is added dropwise within 20 min and stirring is continued for 40 min at 3 C. It is filtered with suction through a frit and the filter cake is mixed with methanol (100 ml), dried and then mixed with methyl-tert.-butyl ether and dried again. After vacuum drying we obtain 26.99 g (84% of th.) of the diazonium tetrafluoroborate salt, which is used further without further purification. For the production of the corresponding indazole derivative, 26.99 g of the diazonium salt (102.2 mmol) is suspended in 500 ml dichloromethane in a 1 l round-bottom flask and 1.43 g (5.4 mmol) of 18-crown-6-ether and 22.8 g (232.1 mmol) of potassium acetate are added at RT and stirred for 3 h at RT. 100 ml water is added to the suspension, the dichloromethane phase is removed and the aqueous phase is extracted once more with dichloromethane. The combined organic phases are washed with 50 ml water and dried over sodium sulphate. Chromatography on silica gel with cyclohexane/ethyl acetate gives 17.54 g (97% of th.) of the product as a solid. LCMS (method 1): Rt=1.41 min (m/z=177 (M+H)+) 1H-NMR (400 MHz, DMSO-d6): delta=13.95 (s, 1H), 8.18 (d, 2H), 7.89 (d, 1H), 7.68 (d, 1H), 3.90 (s, 3H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 3-amino-4-methylbenzoate, its application will become more common.
Reference:
Patent; BAYER HEALTHCARE AG; US2010/105663; (2010); A1;,
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