Oxalic Acid → HCID 20721228, compound

Participants

Reaction Steps

(2R)-Acetylamino-2-methyl(5-(5-phenylpent-1-ynyl)thiophen-2-yl]butyl acetate (1.40 g, 3.40 mmol) obtained in Example 49(a) was dissolved in 14 ml of a mixture solution (tetrahydrofuran:methanol:water 1:1:1), and lithium hydroxide monohydrate (1.43 g, 34.0 mmol) was added thereto followed by stirring for 4 hours at 50° C. The reaction solution was poured into water, extracted with dichloromethane, and after the dichloromethane layer was dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure. The residue was purified by chromatography on a silica gel column (elution solvent; dichloromethane:methanol:ammonia water=20:1:0-10:1:0.1) to afford (2R)-amino-2-methyl-4-[5-(5-phenylpent-1-ynyl)thiophen-2-yl]butan-1-ol (1.11 g, 100% yield). The obtained (2R)-amino-2-methyl-4-[5-(5-phenylpent-1-ynyl)thiophen-2-yl]butan-1-ol (360 mg, 1.10 mmol) was dissolved in methanol, and oxalic acid (99 mg, 1.10 mmol) was added thereto to precipitate crystals. The crystals were recrystallized from methanol to afford the title compound (394 mg, 86% yield) as white crystals.

Provenance & Evidence