Lithium hydroxide, monohydrate → 1-(4-Methoxy-benzenesulfonyl)-2,3,4,7-tetrahydro-1H-azepine-2,3-dicarboxylic acid 2-tert-butyl ester

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Reaction Steps

1-(4-Methoxy-benzenesulfonyl)-2,3,4,7-tetrahydro-1H-azepine-2,3-dicarboxylic acid 3-benzyl ester 2-tert-butyl ester (6g, 12 mmol) is dissolved in a mixture of 120 ml Tetrahydrofuran and 78 ml Water. LiOH.H2O (1 g, 24 mmol) is added. After 45 min., more Water (15 ml) is added and the reaction solution is stirred at room temp. for 24 h. The solvent is evaporated and the remaining solid is resolved in Water/Diethylether. The water layer is acidified to pH 1. The organic phase is separated and the water phase is extracted twice with Ethylacetate. The combined organic fractions are dried with MgSO4 and filtered. The solvent is evaporated to afford the product: Cal. 412.5, found (M)+412.1.

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