Formaldehyde → HCID 21071654, compound

Participants

Reaction Steps

Combine (2-(6-chloro-1H-indol-3-yl)ethyl)-(3-(2,2-difluoroethoxy)benzyl)amine (276 mg, 0.76 mmol) and formaldehyde (55.5 μL of a 38% aqueous solution, 0.76 mmol) in dichloroethane (15 mL) and stir at room temperature for 10 minutes; add in two portions sodium triacetoxyborohydride (321 mg, 1.51 mmol) over 10 minutes and stir at room temperature overnight before diluting with methanol (10 mL) and quenching with one drop of glacial acetic acid. Remove in vacuo the solvent, and redissolve the crude residue in methanol and directly load onto a 10 g SCX column. After washing thoroughly with methanol, elute the column with 2 N ammonia in methanol. Concentrate in vacuo the eluant to give the free base of the title compound as a straw-colored oil. Dissolve the free base (239 mg, 0.64 mmol) in methanol (20 mL) and treat with a solution of ammonium chloride (36 mg, 0.67 mmol) in methanol (5 mL). Sonicate the mixture for 10 minutes before removal of the solvent in vacuo to give the hydrochloride salt as a tacky yellow oil. Dissolve the oil in 10 mL of 1:1 acetonitrile-water and lyophilize overnight, providing a fluffy white solid and triturate with diethyl ether (10 mL) and acetonitrile (2 drops). Filtration and drying of the resulting precipitate afforded the desired hydrochloride as a white amorphous solid: mp: 63.8–65.8° C.; 1H NMR (400 MHz, dmso-d6): 11.10 (br s, 1H), 7.52 (d, 1H, J=8.4 Hz) 7.36 (d, 1H, J=2.0 Hz), 7.40–7.26 (m, 2H), 7.22 (d, 1H, J=2.4 Hz), 7.20–7.11 (m, 1H), 7.04 (br d, 1H, J=7.6 Hz), 6.96 (dd, 1H, J=8.6, 1.4 Hz), 6.38 (tt, 1H, J=54.4, 3.6, Hz), 4.50–4.02 (br m, 2H), 4.30 (td, 2H, J=14.4, 3.2 Hz), 3.15 (br s, 4H), 2.68 (br s, 3H); MS (ES+): m/e 378.9 (M+1); CHN (for C20H21ClF2N2O.HCl.0.7H2O) calcd: C 56.14, H 5.51, N 6.55; found: C 55.72, H 5.32, N 7.07.

Provenance & Evidence