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!

ChemicalBook CAS DataBase List 2-(N-BOC-AMINO)-5-BROMOPYRIDINE
159451-66-8

2-(N-BOC-AMINO)-5-BROMOPYRIDINE synthesis

5synthesis methods
24424-99-5 Synthesis
Di-tert-butyl dicarbonate

24424-99-5
834 suppliers
$13.50/25G

-

Yield: 85%

Reaction Conditions:

Stage #1:5-bromo-2-pyridylamine with sodium hexamethyldisilazane in tetrahydrofuran at 0; for 0.0833333 h;
Stage #2:di-tert-butyl dicarbonate in tetrahydrofuran at 20; for 0.5 h;
Stage #3: with hydrogenchloride in tetrahydrofuran;water; pH=7 - 8

Steps:

1.B 1B. Preparation of tert-Butyl 5-bromopyridin-2-ylcarbamate
To a solution of 2-amino-5-bromopyridine (8.65 g, 50 mmol) in THF (100 mL) at 0° C. was added sodium bis(trimethylsilyl)amide (1 M solution in THF, 105 mL, 105 mmol). After addition, the reaction was stirred at 0° C. for 5 min, and then di-tert-butyl dicarbonate (12 g, 55 mmol) was added in several portions. After addition, the reaction was stirred at RT for 30 min, and then diluted with water (60 mL) and neutralized by adding ice-cold 1N HCl (about 90 mL) to pH=78. The resultant mixture was extracted with EtOAc (3×100 mL). The combined organic layers were washed with saturated NaCl. The organic layer was dried (Na2SO4), filtered and concentrated. The resulting residue was purified by silica gel (330 g) column chromatography eluting with a gradient of EtOAc (0-50%) in hexane to give the title compound as an off-white solid (11.6 g, 85%). LC/MS (method A): retention time=3.47 min, (M+H-tBu))+=217.

References:

Sun, Chongqing;Ewing, William R.;Sulsky, Richard B.;Huang, Yanting US2006/155126, 2006, A1 Location in patent:Page/Page column 8

2-(N-BOC-AMINO)-5-BROMOPYRIDINE Related Search: