تفاعل #461473

معادلة التفاعل

5-(4-hydroxy-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid, methyl ester

2,6-diisopropylphenylisocyanate

→

carbamate

5-[4-[[[[2,6-Bis(1-methylethyl)phenyl]amino]carbonyl]oxy]-2,5-dimethylphenoxy]-2,2-dimethylpentanoic acid, methyl ester

المذيبات

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةat reflux for 18 hours overnight
2. 2
   أخرىThe solvent is removed

الإجراء التجريبي

A mixture of 5-(4-hydroxy-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid, methyl ester, 1.5 g and 1.0 g (5 mmol) of 2,6-diisopropylphenylisocyanate in 75 mL of tetrahydrofuran containing 0.1 g of 4-dimethylaminopyridine is stirred at reflux for 18 hours overnight. The solvent is removed leaving 3.1 g of the title carbamate which crystallizes on standing. The crude precipitate is chromatographed on a 4.5 cm column containing 125 g of silica gel prepared in 1:1 hexane:dichloromethane. Elution with dichloromethane affords 1.8 g of the title compound. Recrystallization from 75 mL of hexane affords the title compound as a colorless solid; mp 111°-112° C.

المصدر