Hydrochloric Acid → HCID 21927758, compound

Participants

Reaction Conditions

Reaction Steps

The pyrazinone, 1-benzyloxycarbonylmethyl-3-dichloro-6-(3-nitrophenyl)pyrazinone (EX-100A), (15.01 g, 34.6 mmol) was taken up in 325 mL of 50% EtOH (w/w) and heated to 75° C. EtOAc was added until the solution was homogeneous (about 80 mL). Iron powder (9.4 g, 168 mmol) was added, followed by 0.57 mL of 12 M HCl (6.8 mmol) in about 0.6 mL of 50% EtOH. The reaction was monitored by TLC (80% EtOAc/hexanes) and was complete within 40 minutes. The reaction mixture was cooled to room temperature, and the iron was removed by filtration through Celite. The yellow solution was diluted with 600 mL of EtOAc and 300 mL of water. Saturated NaCl was added to help separate the layers. The organic phase was washed with saturated NaHCO3 (2×250 mL), saturated NaCl (1×250 mL), dried over MgSO4, filtered, and the solvents were removed under reduced pressure. The residue was taken up in 20–25 mL of 3.4 M HCl in EtOAc. Additional EtOAc (about 25 mL) was added, and the mixture was heated to dissolve all of the compound. The volatile components were removed under reduced pressure. The residue (crusty solid) was taken up in EtOAc and slowly dripped into hexanes. The pale yellow solid that precipitated was filtered and dried under vacuum at room temperature to yield 12.19 g (80% yield) of 1-benzyloxycarbonylmethyl-3,5-dichloro-6-(3-aminophenyl)pyrazinone hydrochloride (EX-100B) as a pale yellow solid: 1H NMR (300 MHz, CD3OD) δ 4.61 (AB q, 2H, J=17 Hz), 5.20 (AB q, 2H, J=12 Hz), 7.31–7.51 (m, 7H), 7.63–7.67 (m, 2H); HPLC purity (retention time): 91% (3.0 min); LRMS m/z 404 (M++H).

Provenance & Evidence