Aluminium lithium hydride → (2-Phenyl-benzofuran-5-yl)-methanol

Beteiligte Stoffe

Reaktionsschritte

To a solution of 2-phenyl-benzofuran-5-carboxylic acid methyl ester 27 (0.7 g, 2.8 mmol) in THF (15 ml) was added dropwise a solution of lithium aluminum hydride (1M in THF) (3.6 ml, 3.6 mmol) at 0° C. After the addition, the reaction mixture was allowed to warm to room temperature and stirred for 2 hrs. The mixture was cooled to 0° C., diluted with ether and sodium sulfate decahydrate was added. After filtration the solids were washed with ether, and the organic layer was washed and dried. Evaporation of the solvent and purification by chromatography yielded (2-phenyl-benzofuran-5-yl)-methanol (0.55 g). A mixture of (2-phenyl-benzofuran-5-yl)-methanol (0.5 g, 2.23 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.55 g, 2.68 mmol), triethylamine (0.74 ml, 5.35 mmol) and THF (15 ml) was heated at 50° C. for 6 hrs. Additional (R) 2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.15 g) was added, and the mixture was stirred at 50° C. overnight. The solvent was evaporated and the residue was partitioned between ethyl acetate and water. After extraction and evaporation of the solvent, the residue was purified by chromatography to give about 0.76 g of (R)-3-phenyl-2-(2-phenyl-benzofuran-5-ylmethoxycarbonylamino)-propionic acid methyl ester 28.

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