Tin tetrachloride → 1'-Trifluoroacetyl-6-(propanoyl)-spiro[3,4-dihydrobenzopyran-2,4'-piperidine]

HRID 38049Notes

Reaction equation

[F:1][C:2]([F:21])([F:20])[C:3]([N:5]1[CH2:10][CH2:9][C:8]2([CH2:15][CH2:14][C:13]3[CH:16]=[CH:17][CH:18]=[CH:19][C:12]=3[O:11]2)[CH2:7][CH2:6]1)=[O:4].[C:22](Cl)(=[O:25])[CH2:23][CH3:24].[Sn](Cl)(Cl)(Cl)Cl>C(Cl)Cl>[F:21][C:2]([F:1])([F:20])[C:3]([N:5]1[CH2:10][CH2:9][C:8]2([CH2:15][CH2:14][C:13]3[CH:16]=[C:17]([C:22](=[O:25])[CH2:23][CH3:24])[CH:18]=[CH:19][C:12]=3[O:11]2)[CH2:7][CH2:6]1)=[O:4]

Participants

Conditions

Temperature: 10 °C

Procedure

A mixture of 1′-trifluoroacetyl-spiro[3,4-dihydrobenzopyran-2,4′-piperidine] (1.49 g, 4.98 mmol) and propanoyl chloride (0.4 mL, 5 mmol) in methylene chloride (13 mL) was cooled at 10° C. Tin tetrachloride (1M solution in methylene chloride) (0.76 mL, 6.5 mmol) was added at 10° C. and stirred at 10° C. for 20 min then quenched with aqueous 2N HCl at 0° C. The aqueous layer was extracted twice with methylene chloride and the combined organics was washed with brine, dried (Na2SO4), filtered, and concentrated to provide a crude product. The crude product was purified by ISCO (80 g column) chromatography using 17 to 35% EtOAc in hexane to produce 1′-trifluoroacetyl-6-(propanoyl)-spiro[3,4-dihydrobenzopyran-2,4′-piperidine] (1.42 g, 81%),

Workup

customthen quenched with aqueous 2N HCl at 0° C
extractionThe aqueous layer was extracted twice with methylene chloride
washthe combined organics was washed with brine
dry with materialdried (Na2SO4)
filtrationfiltered
concentrationconcentrated
customto provide a crude product
customThe crude product was purified by ISCO (80 g column) chromatography

Sources & evidence

ORD record: ord-e5e491d191344dcbbf0dbb275b484d95
Source dataset: uspto-grants-2013_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08524713B2

Reaction notes

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