With the rapid development and complex challenges of chemical substances, the synthesis of new drugs is usually one of the most effective ways to increase yield.78607-32-6, name is 3-Amino-2,5-dichloropyridine, molecular formula is C5H4Cl2N2, molecular weight is 163.0047, as common compound, the synthetic route is as follows.Safety of 3-Amino-2,5-dichloropyridine
A mixture of trimethylchlorosilane and 1,2-dibromoethane (7:5 v/v, 0.125 ml) was added dropwise (keeping the T¡ãC below 50¡ãC) to a suspension of zinc powder (422 mg) in dimethylacetamide (3 ml). The mixture was stirred 20 min at room temperature then a solution of l-(t-butoxycarbonyl)-4-iodo-piperidine (1.62 g, prepared in 2 steps from l-(t-butoxycarbonyl)-piperidin-4-one according to J. Org. Chem. 2004, 5120) indimethylacetamide (3 ml) was added dropwise over 5 min (slightly exothermic). The resulting mixture was stirred at room temperature for 30 min then cannulated into a mixture of 2,5-dichloro-3-aminopyridine (603 mg), copper(I) iodide (42 mg) and PdCl2(dppf) (91 mg) in dimethylacetamide (5 ml). The resulting mixture was stirred at 80¡ãC for 3 hours, cooled to room temperature, poured into water, extracted with ethyl acetate, dried over sodium sulfate and concentrated in vacuo. The residue was subjected to silica gel chromatography (ethyl acetate: cyclohexane 3:7) to afford 3-amino-5-chloro-3′,6′-dihydro-2’H-[2,4′]bipyridinyl-r-carboxylic acid tert-butyl ester (535 mg) as a yellow solid. *H NMR (400 MHz, CDC13) 1.4 (s, 9H), 1.8 (m, 4H), 2.6 (m, 1H), 2.8 (m, 2H), 3.7 (br s, 2H), 4.2 (m, 2H), 6.9 (s, 1H), 7.9 (s, 1H).The product thus obtained (448 mg) was treated as described in Example 1, Steps D and E to afford the title product (455 mg) as a white solid. M.p. 63-67 ¡ãC; *H NMR (400 MHz, CDCI3) 1.9 (m, 2H), 2.2 (m, 4H), 2.7 (m, 1H), 3.2 (m, 2H), 3.3 (m, 2H), 6.2 (dt, J = 18, 9 Hz, 1H), 6.5 (d, J = 18 Hz, 1H), 7.1-7.3 (m, 4H), 7.7 (d, J = 5.2 Hz, 1H), 7.8 (s, 1H), 7.9 (m, 1H, NH), 8.3 (d, J = 2.4 Hz, 1H), 8.4 (d, J = 2.4 Hz, 1H), 8.6 (d, J = 4.8 Hz, 1H), 8.7 (d, J = 5.5 Hz, 1H); Retention Time HPLC 1.53 min; MS (ES+) 501/503/505 (M+H+).
At the same time, in my other blogs, there are other synthetic methods of this type of compound,78607-32-6, 3-Amino-2,5-dichloropyridine, and friends who are interested can also refer to it.
Reference:
Patent; SYNGENTA PARTICIPATIONS AG; WO2006/3494; (2006); A2;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem