1,3-Dibromopropane → Methyl 4-{(4E)-5-[2-(3-bromopropoxy)phenyl]-3-[4-(methoxycarbonyl)benzyl]pent-4-en-1-yl}benzoate

HRID 1512211Notes

Reaction equation

[Br:1][CH2:2][CH2:3][CH2:4]Br.C(=O)([O-])[O-].[K+].[K+].[OH:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=1/[CH:19]=[CH:20]/[CH:21]([CH2:34][C:35]1[CH:40]=[CH:39][C:38]([C:41]([O:43][CH3:44])=[O:42])=[CH:37][CH:36]=1)[CH2:22][CH2:23][C:24]1[CH:33]=[CH:32][C:27]([C:28]([O:30][CH3:31])=[O:29])=[CH:26][CH:25]=1>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C1(C)C=CC=CC=1>[Br:1][CH2:2][CH2:3][CH2:4][O:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=1/[CH:19]=[CH:20]/[CH:21]([CH2:34][C:35]1[CH:36]=[CH:37][C:38]([C:41]([O:43][CH3:44])=[O:42])=[CH:39][CH:40]=1)[CH2:22][CH2:23][C:24]1[CH:33]=[CH:32][C:27]([C:28]([O:30][CH3:31])=[O:29])=[CH:26][CH:25]=1

Participants

Conditions

Temperature: 110 °C

Procedure

1.69 g (8.37 mmol) of 1,3-dibromopropane, 180 mg (0.56 mmol) of tetrabutylammonium bromide and 3.85 g (27.9 mmol) of anhydrous potassium carbonate are added to a solution of 1.24 g (2.79 mmol) of methyl 4-{(4E)-5-(2-hydroxyphenyl)-3-[4-(methoxycarbonyl)benzyl]pent-4-en-1-yl}benzoate (enantiomer 1, Example 19A) in 23 ml of dry toluene, and the mixture is then stirred at 110° C. for 24 h. Another 1.69 g (8.37 mmol) of 1,3-dibromopropane are then added, and the mixture is stirred at 110° C. for a further 24 h. The mixture is then filtered through kieselguhr, and the filtrate is evaporated to dryness. The crude product obtained is purified by flash chromatography on silica gel (mobile phase: dichloromethane). This gives 0.650 g (1.15 mmol, 41.2% of theory) of a colorless oil.

Workup

stirringthe mixture is stirred at 110° C. for a further 24 h
filtrationThe mixture is then filtered through kieselguhr
customthe filtrate is evaporated to dryness

Sources & evidence

ORD record: ord-1f962fe69a184422a663c84a04af0076
Source dataset: uspto-grants-2012_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08217063B2

Reaction notes

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