Trifluoroacetic acid → HCID 70686036, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 20.0 mg (72.4 μmol) of 1,4-dimethyl-6-pentyl-1H-pyrrolo[2,3-b]pyridin-5-yl acetate in 1 mL of CH2Cl2 was added 217 μL (84.0 μmol, 1.0 M in hexanes) of DIBAL-H at 78° C. The reaction mixture was stirred at 78° C. for 1 h and then 2 mL of sat aq sodium potassium tartrate was added slowly. The reaction mixture was slowly warmed to room temperature over a period of 30 min. The solution was extracted with three 5-mL portions of ethyl acetate. The combined organic layer was washed with brine, dried (MgSO4) and concentrated under diminished pressure to give the crude product as a yellow oil: silica gel TLC Rf 0.12 (1:9 MeOH/CH2Cl2). The residue was then dissolved in 1 mL of CH3CN and 1% aq TFA, frozen and lyophilized. The crude product was purified on a Prepex C8 reversed phase semi-preparative (250 mm×10 mm) HPLC column using a gradient of methanol and water. Linear gradients were employed using 1:4 methanol/water→4:1 methanol/water over a period of 20 min, and then 4:1 methanol/water→methanol over a period of 40 min, at a flow rate of 3.5 mL/min (monitoring at 260 nm). Fractions containing the desired product eluted at 21.6 min, and were collected, frozen, and lyophilized to give 1a as a light yellow solid: yield 13.5 mg (80%); 1H NMR (CD3CN) δ 0.88 (t, 3H, J=6.8 Hz), 1.27-1.32 (m, 4H), 1.54 (quint, 2H, J=7.6 Hz), 2.13 (s, 3H), 2.69 (t, 2H, J=8.0 Hz), 2.99 (t, 2H, J=8.4 Hz), 3.06 (s, 3H) and 3.72 (t, 2H, J=8.4 Hz); 13C NMR (CDCl3) δ 13.0, 13.3, 22.1, 24.4, 27.2, 28.3, 31.1, 32.4, 53.1, 117.3, 126.1, 132.1, 140.4, 141.6 and 152.0; mass spectrum, m/z 234.2 (M)+ (theoretical 234.2); mass spectrum (APCI), m/z 235.1806 (M+H)+ (C14H23N2O requires 235.1810).

Provenance & Evidence