Hydrochloric Acid → ethyl 2-(5-(3-(hydroxymethyl)pyridin-2-yl)-1H-pyrazol-1-yl)acetate

Participants

Reaction Conditions

Reaction Steps

To (E)-1-(3-((tert-butyldimethylsilyloxy)methyl)pyridin-2-yl)-3-(dimethylamino)prop-2-en-1-one (crude, 350 mg, 1.09 mmol, 1 eq.) in EtOH (10 mL) was added ethyl 2-hydrazinylacetate hydrochloride (338 mg, 2.18 mmol, 2.0 eq.). The mixture was heated at 80° C. for 2 h, cooled to rt, added HCl (6 N, 0.5 mL), and stirred O/N. The mixture was concentrated, and diluted with a mixture of EtOAc (50 mL) and NaHCO3(sat) (10 mL). The layers were separated and the aqueous layer was extracted with EtOAc three times. The combined organic layers were dried over Na2SO4, concentrated, and purified on silica gel using EtOAc as eluent to give ethyl 2-(5-(3-(hydroxymethyl)pyridin-2-yl)-1H-pyrazol-1-yl)acetate (212 mg, 74%) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 8.61 (dd, J=4.7, 1.6 Hz, 1H), 7.97 (dd, J=7.8, 1.4 Hz, 1H), 7.64 (d, J=1.9 Hz, 1H), 7.36 (dd, J=7.8, 4.8 Hz, 1H), 6.56 (d, J=1.9 Hz, 1H), 5.21 (s, 2H), 4.79 (d, J=5.8 Hz, 2H), 4.09 (q, J=7.1 Hz, 2H), 2.54 (t, J=6.0 Hz, 1H), 1.18 (t, J=7.1 Hz, 31-1). LRMS m/z 262.1

Provenance & Evidence