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ChemicalBook CAS DataBase List Diethyl aMinoMethanephosphonate
50917-72-1

Diethyl aMinoMethanephosphonate synthesis

13synthesis methods
-

Yield: 97%

Reaction Conditions:

with hydrazine hydrate in ethanol at 20;Reflux;

Steps:

4.4.1 Diethyl (aminomethyl)phosphonate (24)
A suspension of N-(bromomethyl)phthalimide (3.6g, 15.0mmol) in triethylphosphite (3.00g, 18.0mmol) was heated to 90°Cfor 3h. A distillation apparatus was then installed and volatile ethyl bromide was removed by reduced pressure distillation. The crude mixture was cooled to room temperature, and the resulting white solid was used without further purification. 1H NMR (300MHz, CDCl3) δ=1.24 (t, J=7.1Hz, 6H, 2×CH3), 4.01 (d, 2JH-P=11.4Hz, 2H, 1×CH2), 4.12 (m, 4H, 2×CH2), 7.73 (dd, J=5.5, 3.1Hz, 2H, 2×CH), 7.86 (dd, J=5.3, 3.0Hz, 2H, 2×CH) ppm. To a solution of this solid (4.5g, 15mmol) in ethanol (20mL) was added hydrazine monohydrate (1.05mL, 21.6mmol) and the resulting mixture was stirred at room temperature overnight, and then refluxed for 3h. The crude mixture was cooled down to 0°C, and the white precipitate was removed by filtration and washed with ice-cold ethanol. The solution was concentrated under vacuum, and the resulting oily residue was purified by column chromatography on silica gel eluting with a gradient of Et2O/ MeOH (80:20→70:30) to afford compound 24 as a pale yellow oil (2.43g, 97%). TLC: Rf=0.30 (silica gel, Et2O/MeOH 80:20, stained with ninhydrin). 1H NMR (300MHz, CD3CN) δ=1.31 (t, J=7.1Hz, 6H, 2×CH3), 1.76 (br, 2H, NH2), 2.94 (d, 2JH-P=10.6Hz, 2H, 1×CH2), 4.08 (quintet, 3JH-H=3JH-P=7.0Hz, 2H, 1×CH2), 4.10 (quintet, 3JH-H=3JH-P=7.1Hz, 2H, 1×CH2) ppm. 31P NMR (121MHz, CDCl3) δ=27.49ppm.

References:

Leygue, Nadine;Perez e I?iguez De Heredia, Aritz;Galaup, Chantal;Benoist, Eric;Lamarque, Laurent;Picard, Claude [Tetrahedron,2018,vol. 74,# 31,p. 4272 - 4287]