(Chloromethyl)triphenylphosphonium chloride → 1-[3-(Chloromethylene)-2,3-dihydro-1-benzoxepin-7-yl]ethanone

HRID 1791062Notes

Reaction equation

C([Li])CCC.[Cl-].[Cl:7][CH2:8][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[C:28]([C:31]1[CH:32]=[CH:33][C:34]2[O:40][CH2:39][C:38](=O)[CH:37]=[CH:36][C:35]=2[CH:42]=1)(=[O:30])[CH3:29]>O1CCCC1.CCCCC>[Cl:7][CH:8]=[C:38]1[CH:37]=[CH:36][C:35]2[CH:42]=[C:31]([C:28](=[O:30])[CH3:29])[CH:32]=[CH:33][C:34]=2[O:40][CH2:39]1

Participants

Conditions

Temperature: 0 °C

Procedure

1.1 equivalents of n-butyllithium are added to 309 mg (0.89 mmol) of chloromethyltriphenylphosphonium chloride in 5 ml of tetrahydrofuran cooled to 0° C. After stirring for one hour, 150 mg (0.74 mmol) of 7-acetyl-1-benzoxepin-3(2H)-one, prepared according to example 79, are added at ambient temperature. The medium is stirred for a further 1 hour. After the usual treatments and evaporating the solvent under reduced pressure, the crude reaction product is taken up in pentane in order to precipitate triphenylphosphine oxide. Evaporation of the solvents provides 95.5 mg (55%) of 1-[3-(chloromethylene)-2,3-dihydro-1-benzoxepin-7-yl]ethanone in the form of a mixture of two Z/E isomers in a 90/10 ratio; 1H NMR (C6D6): 7.85 (d, 1H, J=2.2 Hz), 7.76 (dd, 2.2 Hz and 8.4 Hz), 7.04 (d, 8.4 Hz), 6.85 (d, J-=11.8 Hz, 1H), 6.57 (d, J=11.8 Hz, 1H), 6.16 (s, 1H), 4.57 (4.87) (s, 2H), 2.56 (s, 3H).

Workup

additionare added at ambient temperature
stirringThe medium is stirred for a further 1 hour
customAfter the usual treatments and evaporating the solvent under reduced pressure
customthe crude reaction product
customto precipitate triphenylphosphine oxide
customEvaporation of the solvents

Sources & evidence

ORD record: ord-3b79389c3e42424d85f643dbd66bbb59
Source dataset: uspto-grants-2006_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07071340B2

Reaction notes

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