Electric Literature of 2106-02-7, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 2106-02-7, name is 2-Chloro-4-fluoroaniline belongs to chlorides-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
Lithium hexamethyldisilazide (22.9 ml, 22.9 mmol, 1 M solution in tetrahydrofuran) was added over 5 min to solution of 2-chloro-4-fluoroaniline (1 .84 g, 12.6 mmol, Cas No 2106-02-7) in tetrahydrofuran (60 ml) at -78 and the mixture was stired at -78 for 1 h. A solution of ethyl 4-{[tert-butyl(dimethyl)silyl]oxy}-1-(2-chloroethyl)cyclohexanecarboxylate (mixture of cis-/trans-isomers) (4.00 g, 1 1 .5 mmol) in tetrahydrofuran (60 ml) was added and the mixture was stirred for 2 h at -78 and the for 3 days at room temperature. For work-up, the reaction mixture was poured into a mixture of water and saturated sodium bicarbonate solution, extracteted with ethyl acetate (3x) and the combined organic phases were washed with brine, filtrated through a silicone filter and concentrated under reduced pressured. The residue was purified by flash chromatography (Snap Cartdidge, hexanes/ethyl acetate gradient) to give 8-{[tert-butyl(dimethyl)silyl]oxy}-2-(2-chloro-4-f luorophenyl)-2-azaspiro[4.5]decan-1-one in 2 fractions. Fraction 1 (1 .88 g, isomer 1, contains ca 20mol% 2-chloro-4-fluoroaniline) and fraction 2 (485 mg, isomer 2).Fraction 1 (isomer 1 ):LC-MS (Method 1 ): Rt= 1 .68 min; MS (ESIpos) m/z = 412.2 [M+H]+.1H-NMR (400 MHz, DMSO-d6): delta [ppm] = 7.58 (dd, 1H), 7.46 (dd, 1H), 7.30 (td, 1H), 3.97-3.92 (m, 1H), 3.59 (t, 2H), 2.06 (t, 2H), 2.01-1 .92 (m, 2H), 1.71-1.54 (m, 4H), 1 .36-1 .29 (m, 2H), 0.92-0.86 (m, 9H), 0.08-0.03 (m, 6H).Fraction 2 (isomer 2):LC-MS (Method 1 ): Rt= 1 .67 min; MS (ESIpos) m/z = 412.2 [M+H]+.1H-NMR (400 MHz, DMSO-d6): delta [ppm] = 7.57 (dd, 1H), 7.45 (dd, 1H), 7.33-7.25 (m, 1H), 3.70-3.52 (m, 3H), 2.07 (t, 2H), 1 .84-1 .74 (m, 2H), 1.62-1 .54 (m, 4H), 1 .42-1.28 (m, 2H), 0.89-0.83 (m, 9H), 0.07-0.01 (m, 6H)
The synthetic route of 2-Chloro-4-fluoroaniline has been constantly updated, and we look forward to future research findings.
Reference:
Patent; BAYER PHARMA AKTIENGESELLSCHAFT; BUCHGRABER, Philipp; EIS, Knut; WAGNER, Sarah; SUeLZLE, Detlev; VON NUSSBAUM, Franz; BENDER, Eckhard; LI, Volkhart, Min-Jian; LIU, Ningshu; SIEGEL, Franziska; LIENAU, Philipp; (248 pag.)WO2018/78005; (2018); A1;,
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