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ChemicalBook CAS DataBase List (BROMOMETHYL)TRIPHENYLPHOSPHONIUM BROMIDE
1034-49-7

(BROMOMETHYL)TRIPHENYLPHOSPHONIUM BROMIDE synthesis

4synthesis methods
-

Yield:1034-49-7 82%

Reaction Conditions:

in toluene; for 16 h;Inert atmosphere;Reflux;

Steps:

4-(Bromomethylene)tetrahydro-2H-pyran 42

To a solution of triphenylphosphine (3.3 g, 12.6 mmol) in toluene (10 mL) was added methylene bromide (1.1 mL, 16.4 mmol), dropwise and the resulting solution was heated to reflux and stirred for 16 hours. The precipitate that formed upon cooling was filtered, washed with toluene and dried in vacuo to obtain the phosphonium salt intermediate (bromomethyl)triphenylphosphonium bromide (4.5 g, 82%) as a white solid, which was used immediately without further purification or characterisation. To a suspension of the phosphonium salt in tetrahydrofuran (50 mL) at -78 °C was added potassium tert-butoxide (1.3 g, 11.9 mmol). The mixture was stirred for 1.5 hours before tetrahydro-4H-pyran-4-one (1.0 g, 10.3 mmol) in tetrahydrofuran (3 mL) was added slowly. The mixture was warmed to -40 °C over 1 hour and then stirred at room temperature for a further 2 hours. Water was added (50 mL) and the mixture extracted with diethyl ether (3 x 50 mL). The combined organic extracts were concentrated and the resulting suspension filtered and washed with diethyl ether (10 mL). The filtrate was concentrated and purified by flash column chromatography using ethyl acetate, hexane (3:97) as an eluent to obtain the title compound (670 mg, 37%) as a colourless oil, Rf: 0.46 (1:19 ethyl acetate, hexane); IR (vmax (film)): 2960, 2847, 1234, 1149, 1097, 996, 790, 778 cm-1; 1H NMR (300 MHz, CDCl3): δ 2.20-2.52 (4H, m), 3.58-3.78 (4H, m), 5.96 (1H, s) ppm; 13 C NMR (75 MHz, CDCl3): δ 32.0, 35.9, 68.0, 68.7, 99.7, 140.2 ppm.

References:

Moir, Michael;Boyd, Rochelle;Gunosewoyo, Hendra;Montgomery, Andrew P.;Connor, Mark;Kassiou, Michael [Tetrahedron Letters,2019,vol. 60,# 36,art. no. 151019] Location in patent:supporting information

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