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

Participants

Reaction Steps

To a stirred solution of (S)-methyl 2-(2-(3-chlorophenyl)-7-cyclohexyl-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate (0.067 g, 0.162 mmol) and tert-butyl acetate (1 ml, 7.40 mmol) in CH2Cl2 (3 mL) was added 70% perchloric acid (0.042 ml, 0.486 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-cyclohexyl-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)acetate (0.0481 g, 0.102 mmol, 63.2% yield) as white solid. 1H NMR (500 MHz, CDCl3) δ: 7.96 (t, J=1.5 Hz, 1H), 7.87 (dt, J=7.6, 1.3 Hz, 1H), 7.41-7.31 (m, 2H), 6.75 (s, 1H), 5.40 (s, 1H), 3.87-3.77 (m, 1H), 3.70 (s, 3H), 2.93-2.79 (m, 2H), 2.73 (s, 3H), 1.96-1.85 (m, 2H), 1.77-1.68 (m, 2H), 1.54-1.38 (m, 4H), 1.25 (s, 9H). LCMS (M+H) calcd for C26H33ClN3O3: 470.22. found: 472.4.

Provenance & Evidence