Synthetic Route of 20781-20-8,Some common heterocyclic compound, 20781-20-8, name is (2,4-Dimethoxyphenyl)methanamine, molecular formula is C9H13NO2, 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.
Ethyl bromoacetate (Scheme 28) (10.0 gm, 59.87 mmol) solution in 20.0 mL of anhydrous THF was added dropwise to a solution of (2,4-dimethoxybenzyl)amine (10.0gm, 59.81 mmol) and triethyl amine (6.06 gm, 59.87 mmol) in anhydrous THF (20.0 mL) at 0 C under nitrogen atmosphere. The reaction mixture was warmed to room temperature and stirred overnight. Brine was added 100 mL, and the reaction mixture was extracted with ethyl acetate (2 x 100 mL). Combined extracts were dried over anhydrous MgSO4 and concentrated under reduced pressure. The purification wasperformed using combiFlash chromatography, Gradient: 20:80 to 50:50 v/v Ethylacetate:Hexane. 7.6 gm (yield 50.2 %) of the alkylation product was obtained as a colorless liquid. m/z calculated for C13H19N04 [M+H]: 254; Obtained: 254.1. The ester (7.5 gm, 29.6 mmol) was dissolved in 40.0 mL of methanol. The reaction mixture was cooled and 2N aq. NaOH (88.82 mmol, 44.0 mL) solution was addeddropwise. The reaction mixture was warmed to room temperature and stirred for 2 h. The reaction mixture was diluted with 75.0 mL of water, cooled in ice bath and neutralized down to 5.0 to 4.5 pH using 2N aq. HC1. The excess water was concentrated under reduced pressure and air streamed to obtain white solid powder. The solid was dissolved in 85:15 v/v, DCM:MeOH (100.0 mL) and filtered, the filtrate was evaporated to obtain7.1 gm of carboxylic acid as a white powder (Hygroscopic). m/z calculated for C11H15N04 [M+Na]: 248; Obtained: 248.1.j0448J The above compound (7.0 gm, 31.08 mmol) and 6.14 gm, 31.08 mmol of 5- chloroisatoic anhydride were mixed in 70.0 mL of p-Xylene and refluxed at 140 C temperature for 3 h. The reaction mixture filtered and crude product recrystallized frommethanol. 8.5 gm of 7-chloro-4-[(2,4-dimethoxyphenyl)methyl]-2,3,4,5-tetrahydro -1H-1,4-benzodiazepine-2,5-dione was obtained as a white powder (75.8 % yield). m/z calculated for C18H17C1N204 [M+H]: 361; Obtained: 361.1.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route (2,4-Dimethoxyphenyl)methanamine, its application will become more common.
Reference:
Patent; MEKONNEN, Belew; BUTERA, John, A.; HUANG, Jianxing; (400 pag.)WO2016/205739; (2016); A1;,
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