Ethylparaben → 4-[4-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-cyclohexyloxy]-benzoic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of 2-(4-hydroxycyclohexyl)isoindole-1,3-dione (8.0 g, 32.6 mmol) in dry THF (100 mL) was added triphenyl phosphine (12.8 g, 48.8 mmol) and 4-hydroxy benzoic acid ethyl ester (5.44 g, 32.7 mmol). The reaction mixture was cooled to 0° C. and DIAD (9.6 g, 47.4 mmol) was added dropwise from an addition funnel over a period of 3 h. The reaction was gradually brought to room temperature and stirring continued for 3 h. The solvent was removed under vacuum and ether (100 mL) was added and cooled to 0° C. The solid formed was filtered and the clear filtrate concentrated and purified by column chromatography over neutral alumina (8% AcOEt in hexane) to give 5.13 g (42%) of 4-[4-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-cyclohexyloxy]-benzoic acid ethyl ester.

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