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

Participants

Reaction Steps

To a stirred solution of (S)-methyl 2-(2-(3-chlorophenyl)-7-isobutyl-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate (0.059 g, 0.152 mmol) and tert-butyl acetate (1 ml, 7.40 mmol) in CH2Cl2 (3 mL) was added 70% perchloric aci (0.039 ml, 0.456 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-isobutyl-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)acetate (0.0357 g, 0.080 mmol, 52.9% yield) as brown paste. 1H NMR (500 MHz, CDCl3) δ: 7.97 (t, J=1.7 Hz, 1H), 7.86 (dt, J=7.6, 1.3 Hz, 1H), 7.40-7.31 (m, 2H), 6.79 (s, 1H), 5.36 (s, 1H), 3.70 (s, 3H), 3.53 (dd, J=13.4, 7.6 Hz, 1H), 3.14 (dd, J=13.4, 7.0 Hz, 1H), 2.69 (s, 3H), 2.65-2.54 (m, 1H), 1.25 (s, 9H), 1.03 (d, J=6.7 Hz, 3H), 0.98 (d, J=6.7 Hz, 3H). LCMS (M+H) calcd for C24H31ClN3O3: 444.21. found: 444.3.

Provenance & Evidence