Trifluoroacetic acid → 2-Amino-6,6-dimethylfuro[3,4-d]thiazol-4(6h)-one
Reaction equation
[CH3:1][C:2]1([CH3:19])[C:9]2[S:8][C:7]([NH:10]C(=O)OC(C)(C)C)=[N:6][C:5]=2[C:4](=[O:18])[O:3]1.FC(F)(F)C(O)=O>ClCCl>[NH2:10][C:7]1[S:8][C:9]2[C:2]([CH3:1])([CH3:19])[O:3][C:4](=[O:18])[C:5]=2[N:6]=1Participants
4
Procedure
To a solution of Example 5A (7.4 g, 26.0 mmol) in dichloromethane (20 mL) was added trifluoroacetic acid (20.0 ml, 260 mmol) slowly at 0° C. The reaction mixture was removed from the ice bath, allowed to reach room temperature and stirred for 3 hours. The reaction mixture was concentrated to dryness, diluted with ethyl acetate (100 mL) and neutralized with saturated NaHCO3 solution. The layers were separated and the aqueous layer was extracted with ethyl acetate (5×100 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated to give 4.8 g (99%) of product as a white solid. MS (ESI+) m/z 185 (M+H)+.