Guanidine Hydrochloride → Hydrochloric Acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,2-diphenylethanone (500 mg, 2.55 mmol), 3-ethoxy-4-hydroxy-5-nitrobenzaldehyde (538.5 mg, 2.55 mmol), guanidine hydrochloride (731 mg, 7.65 mmol), diisopropylamine (1.1 mL) in ethanol (5 mL) was refluxed at 80° C. for 60 h. The mixture was evaporated under reduced pressure and the residue was treated with a mixture of saturated aqueous sodium bisulfite solution (50 mL), dichloromethane (100 mL) and isopropanol (30 mL), and the resulting mixture was stirred at room temperature for 30 min. The organic layer was separated and the aqueous layer was extracted with a mixture of dichloromethane and isopropanol (3:1, 50 mL×2). The combined organic layer was dried over anhydrous sodium sulfate and purified by preparative HPLC. The product containing fractions were treated with HCl/MeOH (2 mL, 2 N) and concentrated in vacuo to give Compound 112 as an HCl salt (280 mg, yield 25.45%). 1H NMR (DMSO-d6 400 MHZ): δ 10.48 (s, 1H), 10.27 (s, 1H), 9.35 (s, 1H), 7.59 (s, 2H), 7.53 (s, 1H), 7.52-7.31 (m, 5H), 7.26 (d, J=2.0 Hz, 1H), 7.12-7.10 (m, 3H), 6.92-6.90 (m, 2H), 5.57 (d, J=3.2 Hz, 1H), 4.1-4.06 (q, J=7.2 Hz, 2H), 1.36-1.32 (t, J=7.2 Hz, 3H); MS (ESI): m/z 431.0 [M+H]+.

Provenance & Evidence