Diisobutylaluminum hydride → (+/-)-2-[3-(2,4-Dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazol-7-yloxy]-pentan-1-ol

HRID 1671299Notes

Reaction equation

C([O:3][C:4](=O)[CH:5]([O:9][C:10]1[C:11]([CH3:27])=[N:12][N:13]2[C:17]([C:18]3[CH:23]=[CH:22][C:21]([Cl:24])=[CH:20][C:19]=3[Cl:25])=[C:16]([CH3:26])[O:15][C:14]=12)[CH2:6][CH2:7][CH3:8])C.CC(C[AlH]CC(C)C)C.[Cl-].[NH4+]>C1COCC1>[Cl:25][C:19]1[CH:20]=[C:21]([Cl:24])[CH:22]=[CH:23][C:18]=1[C:17]1[N:13]2[N:12]=[C:11]([CH3:27])[C:10]([O:9][CH:5]([CH2:6][CH2:7][CH3:8])[CH2:4][OH:3])=[C:14]2[O:15][C:16]=1[CH3:26]

Participants

Conditions

Temperature: 0 °C

Procedure

To a cooled (0° C.), stirring solution of 2-[3-(2,4-dichloro-phenyl)-2,6-dimethyl-pyrazolo[5,1-b]oxazol-7-yloxy]-pentanoic acid ethyl ester (85 mg, 0.200 mmol) in THF (2.0 ml) at is added DIBAL-H (0.400 ml, 0.400 mmol). The reaction mixture is warmed to RT and stirred for 2 hours. The mixture is added to sat. ammonium chloride (50 ml) and the product is extracted into EtOAc (2×50 ml). The combined organics are washed with brine, dried over MgSO4 and concentrated in vacuo. The crude product is purified by ISCO combiflash chromatography, eluting with 0 to 100% (iso-hexane/EtOAc) on a 12 g SiO2-column to yield the title compound as a white solid; MS: m/z 385.13 [M+H]+.

Workup

temperatureThe reaction mixture is warmed to RT
extractionthe product is extracted into EtOAc (2×50 ml)
washThe combined organics are washed with brine
dry with materialdried over MgSO4
concentrationconcentrated in vacuo
customThe crude product is purified by ISCO combiflash chromatography
washeluting with 0 to 100% (iso-hexane/EtOAc) on a 12 g SiO2-column

Sources & evidence

ORD record: ord-c2fafe9d07cd4dbbac376ea3b8d13710
Source dataset: uspto-grants-2011_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07994203B2

Reaction notes

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