Hydrochloric Acid → 1-Acetyl-3-(2-methoxycarbonylamino-3-methyl-butyryl)-imidazolidine-4-carboxylic acid methyl ester

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Reaction Steps

3-(2-Methoxycarbonylamino-3-methyl-butyryl)-imidazolidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-methyl ester (465 mg, 1.2 mmol) was dissolved in dichloromethane (1 mL) and HCl (4M dioxane, 3 mL) was added. The resultant suspension was stirred at room temperature for 30 minutes, after which all volatiles were removed in vacuo. The crude material was dissolved in THF and diisopropyl ethylamine (154 mg, 1.2 mmol) was added, followed by acetic anhydride (122 mg, 1.2 mmol). The reaction was stirred at room temperature. After 30 minutes, all volatiles were removed in vacuo. The crude material was purified by silica gel chromatography (eluent: DCM/MeOH) to yield the product 1-Acetyl-3-(2-methoxycarbonylamino-3-methyl-butyryl)-imidazolidine-4-carboxylic acid methyl ester (273 mg, 0.829 mmol): LCMS-ESI+: calc'd for C14H23N3O6: 329.4 (M+). Found: 330.4 (M+H+).

Provenance & Evidence