Synthetic Route of 76537-18-3, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 76537-18-3 as follows.
A mixture of 3-bromo-5-chloropyrazin-2-amine (545 mg, 2.61 mmol, D-L Chiral Chemicals) and [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene](3-chloropyridyl)palladium(II) dichloride (178 mg, 0.261 mmol) in DMA (18.2 mL) was degassed. Separately, a vial was charged with zinc (freshly activated and dried according to the procedure found in WO2011/143365, 1.49 g, 22.8 mmol) and the vial was flushed with N2 and heated with a heat gun, then cooled. Dry THF (20 mL) was added. 1,2-Dibromoethane (0.20 mL, 2.4 mmol) was added and the mixture was heated with a heat gun to reflux, and then cooled to room temperature. This heating and cooling cycle was performed three times. TMSCl (0.60 mL, 4.7 mmol) was added. The mixture was heated to 50 C. in an oil bath, and ethyl 3-iodocyclobutane-1-carboxylate (2.0 g, 7.9 mmol, prepared as described in WO2014/200882, the disclosure of which is incorporated herein by reference in its entirety) in THF (10 mL) was added dropwise. The mixture was maintained at 50 C. for about 1 hour, then was cooled to room temperature and degassed by bubbling a stream of nitrogen through the mixture for 5 min. This mixture was then added to the solution of 3-bromo-5-chloropyrazin-2-amine above, excluding zinc solids. The reaction was heated to 50 C. for 1.75 hours, then to 80 C. for 45 minutes. Upon cooling to room temperature, the reaction mixture was partitioned between EtOAc and water. The aqueous layer was extracted again with EtOAc. The combined organic extracts were washed with brine, dried over Na2SO4, filtered, and concentrated. The product was purified via flash chromatography, eluting with a gradient from 0-75% EtOAc in hexanes to afford product (0.35 g, 52%). The cis- and trans-isomers are partially separable, however the product was carried as a mixture to the following step. LCMS calculated for C11H15ClN3O2(M+H)+: m/z=256.1, found: 256.0. First diastereomer to elute: 1H NMR (400 MHz, CDCl3) delta 7.97-7.73 (s, 1H), 4.64-4.32 (s, 2H), 4.29-4.14 (q, J=7.1 Hz, 2H), 3.72-3.52 (m, 1H), 3.27-3.10 (m, 1H), 2.80-2.51 (m, 4H), 1.35-1.25 (t, J=7.1 Hz, 3H). Second diastereomer to elute: 1H NMR (400 MHz, CDCl3) delta 7.98-7.78 (s, 1H), 4.59-4.45 (s, 2H), 4.21-4.12 (q, J=7.1 Hz, 2H), 3.47-3.35 (p, J=8.8 Hz, 1H), 3.26-3.15 (m, 1H), 2.77-2.57 (m, 4H), 1.31-1.25 (t, J=7.2 Hz, 3H).
According to the analysis of related databases, 76537-18-3, the application of this compound in the production field has become more and more popular.
Reference:
Patent; Incyte Corporation; Shepard, Stacey; Combs, Andrew P.; Falahatpisheh, Nikoo; Shao, Lixin; (96 pag.)US2019/276435; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem