Electric Literature of 57951-72-1, A common heterocyclic compound, 57951-72-1, name is 1-Bromo-2-cyclopropylethyne, molecular formula is C5H5Br, its 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.
(0186) Lithium chloride (4.24 g) and 3 zinc powder (9.15 g) were dried under reduced pressure, and 4 tetrahydrofuran (THF) (100 mL), 5 1,2-dibromoethane (0.433 mL) and 6 trimethylchlorosilane (0.127 mL) were added thereto at room temperature. To the mixture was added dropwise a solution of 7 methyl (R)-3-iodo-2-methylpropionate (22.8 q) in THF (30 mL), and the mixture was stirred at 40 C. for 1.5 hr to prepare an organozinc reagent. In another reaction container were added 8 lithium chloride (7.63 g), 9 copper(I) cyanide (8.06 g) and THF (90 mL), and the mixture was stirred for 1 hr. The mixture was cooled to -10 C., and the aforementioned organo zinc reagent was added dropwise thereto. The reaction mixture was stirred at -10 C. for 10 min, cooled to -78 C., and a solution of 10 2-(bromoethynyl)cyclopropane (14.5 g) in THF (50 mL) was added dropwise. The mixture was stirred at the same temperature for 15 hr and poured into an aqueous ammonium chloride solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, and the insoluble material was filtered off and washed with ethyl acetate. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (diethyl ether_hexane=1:30-1:5) to give the 11 title compound (9.93 g). Yield: 66%. (0187) 1H NMR (400 MHz, CDCl3) delta 3.69 (s, 3H), 2.59 (dq, J=6.8, 7.2 Hz, 1H), 2.46 (ddd, J=2.0, 6.0, 16.4 Hz, 1H), 2.29 (ddd, J=2.0, 7.8, 16.4 Hz, 1H), 1.23 (d, J=7.2 Hz, 3H), 1.22 (m, 1H), 0.71 (m, 2H), 0.60 (m, 2H). R
The synthetic route of 57951-72-1 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; AGC INC.; NIPPON ZOKI PHARMACEUTICAL CO., LTD.; YASUDA, Arata; MATSUMURA, Yasushi; SAWADA, Kazuyoshi; NANBA, Hiroyoshi; TAGUCHI, Kazuki; US2019/135743; (2019); A1;,
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