Ethyl 2-(t-BOC-amino)oxazole-5-carboxylate synthesis

Yield:941294-50-4 79%

Reaction Conditions:

with dmap;N-ethyl-N,N-diisopropylamine in N,N-dimethyl-formamide at 20;

Steps:

5b.1

To a solution of ethyl 2-aminooxazole-5-carboxylate (200 mg, 1 eq.) in dry DMF (2 mL) was added BOC-anhydride (418 mg, 1 .2 eq.), DIPEA (0.6 mL, 3 eq.) and finally DMAP (78 mg, 0.5 eq.). The reaction mixture was allowed to stir at RT overnight. After completion of the reaction, the reaction mixture was concentrated under reduced pressure, and water was added. The product was extracted with DCM. The organic phase was concentrated under reduced pressure and the residue was subjected to flash chromatography to afford ethyl 2-((te/?-butoxycarbonyl)amino)oxazole-5-carboxylate as an off-white solid. Yield: 79% (1 .3 g). LC/MS: (Method A) 257.0 (M+H). H NMR (400 MHz, DMSO-d₆): 1 1 .3 (s, 1 H), 7.8 (s, 1 H), 4.29-4.27 (m, 2H), 1 .5 (s, 9H), 1 .3 (t, J = 8.0 Hz, 3H).

References:

WO2014/159234,2014,A1 Location in patent:Page/Page column 78