With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.154590-35-9,tert-Butyl 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylate,as a common compound, the synthetic route is as follows.
Step A. 4-{2-Fluoro-4-[(R-tetrahvdro-furan-3-carbonyl)-amino1-phenyl)- piperazine-1-carboxylic acid tert-butyl ester. A mixture of 4-(4-Amino-2-fluoro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (0.7 g, 2.4 mmol), (R)-tetrahydro-furan-3-carboxylic acid (0.33 g, 2.9 mmol) and HATU (1.1 g, 2.9 mmol) was dissolved into DMF (15.0 ml.) and stirred for 1 h at room temperature. The resulting mixture was diluted with ethyl acetate (200 mL) and washed with 1 N NaOH (30 mL) and then with water (2x 200 mL), dried (Na2SO4), filtered and concentrated to dryness to yield a residue. Chromatography of the residue (SiO2, 0-5 % acetone/DCM) yielded the title compound. MS (ESI) mass calculated for C20H28FN3O4, 393.46, m/z measured, 394.6 [M+H]+1H NMR (CDCI3): 7.50-7.40 (m, 2H), 7.1 1-7.06 (m, 1 H), 6.86 (t, J = 9.0, 1 H), 4.09-3.98 (m, 2H), 3.97-3.90 (m, 1 H), 3.88-3.80 (m, 1 H), 3.62-3.54 (m, 4H), 3.08-2.92 (m, 5H), 2.30-2.20 (m, 2H), 1.48 (s, 9H).
154590-35-9, As the paragraph descriping shows that 154590-35-9 is playing an increasingly important role.
Reference：
Patent; JANSSEN PHARMACEUTICA N.V.; WO2009/79597; (2009); A1;,
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