tert-Butyl acetate → (S)-methyl 2-(tert-butoxy)-2-(2-(3-chlorophenyl)-7-(4-fluorophenyl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)acetate

Participants

Reaction Steps

To a stirred solution of (S)-methyl 2-(2-(3-chlorophenyl)-7-(4-fluorophenyl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate (0.06 g, 0.141 mmol) and tert-butyl acetate (0.952 ml, 7.04 mmol) in CH2Cl2 (3 mL) was added 70% perchloric acid (0.036 ml, 0.423 mmol) at rt. After 2 h, the reaction was diluted with Et2O (50 mL), washed with sat. Na2CO3 (2×5 mL), dried (Na2SO4), filtered and concentrated to give yellow solid which was purified by prep-HPLC to afford (S)-methyl 2-(tert-butoxy)-2-(2-(3-chlorophenyl)-7-(4-fluorophenyl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)acetate (0.0478 g, 0.099 mmol, 70.4% yield) as while solid. 1H NMR (500 MHz, CDCl3) δ: 7.83 (s, 1H), 7.77-7.69 (m, 2H), 7.67-7.62 (m, 1H), 7.35-7.26 (m, 4H), 6.87 (s, 1H), 5.07 (s, 1H), 3.81 (s, 3H), 2.66 (s, 3H), 0.96 (s, 9H). LCMS (M+H) calcd for C26H26ClFN3O3: 482.16. found: 482.3.

Provenance & Evidence