成人免费xx,国产又黄又湿又刺激不卡网站,成人性视频app菠萝网站,色天天天天

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

443770-52-3

3,5-DIBROMO-2,4-DIMETHOXYPYRIDINE synthesis

2synthesis methods
-

Yield:443770-52-3 96%

Reaction Conditions:

with bromine;sodium acetate;acetic acid at 80; for 16 h;Inert atmosphere;Schlenk technique;

Steps:

3,5-dibromo-2,4-dimethoxypyridine (4)

A suspension of 2,4-dimethoxypyridine (5 g, 35.93 mmols), sodium acetate (8.84 g, 107.80 mmols) and bromine (5.52 mL, 107.80 mmols) in 30 mL acetic acid was heated for 16 h to 80 °C and subsequently cooled down to rt 50 mL 10% NaOH (aq.) and 250 mL sat. sodium thiosulfate (aq.) were added to the reaction mixture. The aqueous layer was extracted with EtOAc (5 x 50 mL) and the combined organic layers were dried over anhydrous magnesium sulfate. The product was dried in vacuo. Purification of the crude was performed by silica gel column chromatography (1% EtOAc/n-pentane) to obtain the product (10.24 g, 34.47 mmols, 96%) as a white solid. Rf: 0.28 (2% EtOAc/PE). 1H-NMR (400 MHz, CDCl3): δ = 3.95 (s, 3H), 3.99 (s, 3H), 8.14 (s, 1H). 13C-NMR (126 MHz, CDCl3): δ = 55.19, 60.90, 102.49, 107.92, 147.29, 161.53, 162.55. ESI-MS: m/z = 296.15, 298.01, 299.96 [M+H]+.

References:

Robke, Lucas;Rodrigues, Tiago;Schr?der, Peter;Foley, Daniel J.;Bernardes, Gon?alo J.L.;Laraia, Luca;Waldmann, Herbert [Tetrahedron,2018,vol. 74,# 35,p. 4531 - 4537] Location in patent:supporting information