Phthalic Anhydride → (2S)-5-(Benzyloxy)-2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-5-oxopentanoic acid

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Reaction Steps

16 g of L-glutamic acid γ-benzyl ester and 11 g of phthalic anhydride, both finely powdered, were stirred in 20 ml of toluene at reflux temperature for 2 hours. 50 ml of toluene were added and the mixture was evaporated. A further 80 ml of toluene were then added and the mixture was left to crystallize. Recrystallization from toluene yielded 15 g of α(S)-(2-benzyloxycarbonylethyl)-1,3-dihydro-1,3-dioxo-2-isoindoleacetic acid of melting point 96°-98° C.; [α]D20 =-50.4° (c=1 in methanol).

Provenance & Evidence