Glycine tert-butyl ester → Tert-butyl 2-(2,2-dimethylchroman-6-sulfonamido)acetate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To the solution of 2,2-dimethylchroman-6-sulfonyl chloride (3.165 g, 10.92 mmol) in DCM (50 mL) at −30° C. was added tert-butyl 2-aminoacetate (2.308 mL, 16.39 mmol), Hunig'sBase (3.82 mL, 21.85 mmol), and catalytic amount of DMAP. The mixture was stirred at 25° C. overnight while the reddish orange color of the reaction mixture turned bright yellow. The crude reaction mixture was diluted with EtOAc, washed with dilute aqueous hydrochloric acid solution, then aqueous NaHCO3 solution and brine. The organic layer was dried over MgSO4 and removed on a rotavapor to give a creamy powder. The crude material was purified by silica chromatography (15-30% EtOAc/Hexanes) to yield 3.6 grams of an off white powder (88%). 1H NMR (500 MHz, CDCl3) δ 7.58 (d, J=2.1 Hz, 1H), 7.55 (dd, J=8.6, 2.3 Hz, 1H), 6.81 (t, J=10.6 Hz, 1H), 4.90 (s, 1H), 3.64 (d, J=5.1 Hz, 2H), 2.81 (t, J=6.7 Hz, 2H), 1.81 (t, J=6.7 Hz, 2H), 1.35 (s, 9H), 1.34 (s, 6H). LRMS [ESI, (M−H)−] m/z calcd for C17H24NO5S 354.14, found 354.2.

Herkunft & Nachweise