Diisobutylaluminum hydride → (7-Bromo-5-methyl-2,3-dihydrobenzo[b]oxepin-4-yl)methanol

To a stirred solution of methyl 7-bromo-5-methyl-2,3-dihydrobenzo[b]oxepine-4-carboxylate from step H5 (2.0 g, 6.73 mmol), in THF (75 mL) was added DIBAL-H/THF (1.0 M, 67.3 mL, 67.3 mmol) at −60° C. The mixture was allowed to warm to rt over 3 h. The reaction was chilled to −78° C. and additional DIBAL-H in THF (5.0 equivalents) was added. The reaction was again allowed to warm to rt over 3 h. After an additional 20 h, the reaction mixture was carefully quenched with water. The aqueous mixture was extracted with diethyl ether. The organic layer was concentrated in vacuo. The residue was purified by silica-gel column chromatography (hexanes-50% EtOAc) to give (7-bromo-5-methyl-2,3-dihydrobenzo[b]oxepin-4-yl)methanol (1.53 g, 5.68 mmol, 84% yield). MS (M+H-water)+=251.

1. temperatureThe reaction was chilled to −78° C.
2. temperatureto warm to rt over 3 h
3. customthe reaction mixture was carefully quenched with water
4. extractionThe aqueous mixture was extracted with diethyl ether
5. concentrationThe organic layer was concentrated in vacuo
6. customThe residue was purified by silica-gel column chromatography (hexanes-50% EtOAc)

ORD record

ord-93df268463eb407db9008f91a42430e6

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08604024B2