反应详情

To a pale yellow solution of 6,8-difluoro-7-hydroxy-4-methylcoumarin (Compound 5, 0.13 g, 0.61 mmol) in THF (5 mL) under air at room temperature is added a solution of 4-guanidinobenzoic acid hydrochloride (132 mg, 0.61 mmol) in 4 mL water, followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC; 125 mg, 0.65 mmol). The resulting solution is stirred at room temperature overnight, followed by the addition of more EDC (100 mg). After two hours, TLC analysis indicates the starting materials are consumed. Volatiles are removed in vacuo, and a portion of the residue (0.61 g of pale yellow powder) is purified by chromatography on SEPHADEX LH-20 resin using water:dioxane (1:1) as eluant to give nonfluorescent Compound 35 as a colorless powder: Rf =0.30 (MeCN:H2O:AcOH 90:5:5). Upon treatment with ammonia vapor, a TLC spot corresponding to Compound 35 becomes blue fluorescent.

1. waitAfter two hours
2. customare consumed
3. customVolatiles are removed in vacuo
4. customa portion of the residue (0.61 g of pale yellow powder) is purified by chromatography on SEPHADEX