Some common heterocyclic compound, 37466-90-3, name is Ethyl 3,4-diaminobenzoate, molecular formula is C9H12N2O2, 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. HPLC of Formula: C9H12N2O2
General procedure: The mixture of ethyl 3,4-diaminobenzoate 19 (1 eq., 13.6 mmol), appropriate carboxyaldehyde (1,5 eq., 20.4 mmol) and p-toluenesulphonic acid (0,2 eq., 2.72 mmol) in toluene (150 mL) was heated at reflux with Dean-Stark apparatus for 6 h. After completion of the reaction (TLC control) the whole was concentrated and chromatographed on silica gel (heptane/ethyl acetate, gradient 0-60 % or CHCl3/MeOH 0-5 %). 4.1.14.1 Ethyl 2-(1,3-thiazol-2-yl)-1H-1,3-benzodiazole-6-carboxylate (20h) Synthesized from 19 (5,0 g, 27,7 mmol, 1 eq.) and 2-thiazolecarboxaldehyde (3,56 g, 30,5 mmol, 1,1 eq.). Solid, 7,4 g (yield 88 %). 1H NMR (300 MHz, CDCl3): delta 8.88 (d, J = 0.9 Hz, 1H), 8.01 (d, J = 3.2 Hz, 1H), 7.91 (d, J = 1.8 Hz, 1H), 7.83 (dd, J = 8.4, 1.9 Hz, 1H), 7.50 (dd, J = 3.2, 1.0 Hz, 1H), 6.75 (d, J = 8.4 Hz, 1H), 4.75 (s, 2H), 4.34 (q, J = 7.1 Hz, 2H), 1.39 (dd, J = 8.7, 5.6 Hz, 3H). API-ES: m/z 272.1 [M-H]-
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 37466-90-3, its application will become more common.
Reference:
Article; Moszczy?ski-P?tkowski, Rafa?; Majer, Jakub; Borkowska, Ma?gorzata; Bojarski, ?ukasz; Janowska, Sylwia; Mat?oka, Miko?aj; Stefaniak, Filip; Smuga, Damian; Bazyd?o, Katarzyna; Dubiel, Krzysztof; Wieczorek, Maciej; European Journal of Medicinal Chemistry; vol. 155; (2018); p. 96 – 116;,
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