Sulfuric acid magnesium salt (1:1) → HCID 22278698, compound

Participants

Reaction Steps

A 250 mL dry round bottom flask equipped with a magnetic stir bar was charged with a solution of ethyl 3-{[3,6-diethyl-5-(3-methoxy-5,6,7,8-tetrahydronaphthalen-2-yl)pyrazin-2-yl]amino}butanoate (Example 38, 2.82 g, 6.62 mmol), in THF (37.6 mL) and cooled with an ice bath. A solution of 1M LAH in THF (33.11 mL, 33.11 mmol) was added to the reaction mixture dropwise. Strong effervescence was observed. The reaction was stirred at ° C. for an additional 15 minutes after the addition was complete, then the ice bath was removed and the reaction stirred at ambient temperature for 2 hours. The reaction color changed from pale yellow to brown. The reaction was cooled with an ice bath again, and quenched with ethyl acetate (33 mL) followed by the dropwsie addition of a saturated aqueous solution of KHSO4 (6.62 mL). Effervescence was observed again. After stirring at ° C. for 20 minutes the ice bath was removed. The addition of KHSO4 caused a gel to form, which turned into a solid within 30 minutes. MgSO4 was added to the mixture, and the heterogeneous solution was filtered through MgSO4. After rinsing with ethyl acetate, the filtrated was concentrated to give 2.74 grams of an auburn oil. This material was purified by Biotage MPLC (120 g column, 5% acetone in toluene) to give 2.16 grams (85%) of 3-{[3,6-diethyl-5-(3-methoxy-5,6,7,8-tetrahydronaphthalen-2-yl)pyrazin-2-yl]amino}butan-1-ol as a white foam. Rf 0.20 (40% ethyl acetate in heptane). IR (diffuse reflectance) 2965, 2931, 2875, 2859, 2835, 1572, 1493, 1463, 1445, 1391, 1309, 1248, 1232, 1205, 1171 cm−1. OAMS supporting ions at: ESI+ 384.2. HRMS (ESI) calcd for C23H33N3O2+H1 384.2651. found 384.2667. HRMS (ESI) calcd for C23H33N3O2+H1 384.2651. found 384.2667.

Provenance & Evidence