Acetic Anhydride → HCID 68688605, compound

HRID 1158902Notes

Reaction equation

HRID 1158902 reaction equation
[O:1]1[C:5]([CH:6]=[O:7])=[CH:4][C:3]2[CH2:8][CH2:9][CH2:10][C:2]1=2.[Mg+2].[Br-].[Br-].[N+:14]([C:17]1[CH:35]=[CH:34][C:20]([CH2:21][O:22][C:23]([C:25]2[N:26]3[C@H:29]([S:30][CH:31]=2)[C@@H:28]([Br:32])[C:27]3=[O:33])=[O:24])=[CH:19][CH:18]=1)([O-:16])=[O:15].[C:36](OC(=O)C)(=[O:38])[CH3:37]>CN(C1C=CN=CC=1)C.C(OCC)(=O)C.CCN(CC)CC.C1COCC1.C(#N)C>[N+:14]([C:17]1[CH:35]=[CH:34][C:20]([CH2:21][O:22][C:23]([C:25]2[N:26]3[C@H:29]([S:30][CH:31]=2)[C:28]([CH:6]([O:7][C:36](=[O:38])[CH3:37])[C:5]2[O:1][C:2]4[CH2:10][CH2:9][CH2:8][C:3]=4[CH:4]=2)([Br:32])[C:27]3=[O:33])=[O:24])=[CH:19][CH:18]=1)([O-:16])=[O:15]

Participants

10

Reactant 4

HCID 7918Acetic AnhydrideHCID 82241Magnesium BromideHCID 11280588(5R,6S)-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl esterHCID 21941405HCID 21941405, compound

Product 1

HCID 68688605HCID 68688605, compoundYield 61%

Reagents, catalysts & solvents 5

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6342AcetonitrileSolvent2×HCID 8028TetrahydrofuranSolventHCID 8471TriethylamineSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-20 °C

Procedure

The acetonitrile solution (50 mL) of 5,6-dihydro-4H-cyclopenta[b]furan-2-carbaldehyde (1.33 g) was added to the dry acetonitrile (101 mL) solution of anhydrous MgBr2 (cont. 98%) (5.52 g) under a nitrogen atmosphere at room temperature. The dry THF solution (151 mL) of (5R,6S)-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (cont. 96.5%) (3.91 g) was added to the mixture, cooled to −20° C., and Et3N (cont. 99%) (8.28 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at −20° C. and treated with acetic anhydride (cont. 97%) (4.13 mL) and DMAP (cont. 99%) (121 mg) in one portion. The reaction mixture was warmed to 0° C. and stirred for 16 h at 0° C. The mixture was diluted with ethyl acetate and washed with 5% aqueous solution of citric acid, saturated sodium hydrogen carbonate and brine. The organic layer was dried (MgSO4) then filtered. The filtrate was concentrated under reduced pressure. The residue was purified with a silica-gel column chromatography (n-hexane:AcOEt=4:1-3:1) to give the titled compound as a brown amorphous solid (3.34 g, 61%).

Workup

  1. temperatureThe reaction mixture was warmed to 0° C.
  2. stirringstirred for 16 h at 0° C
  3. washwashed with 5% aqueous solution of citric acid, saturated sodium hydrogen carbonate and brine
  4. dry with materialThe organic layer was dried (MgSO4)
  5. filtrationthen filtered
  6. concentrationThe filtrate was concentrated under reduced pressure
  7. customThe residue was purified with a silica-gel column chromatography (n-hexane:AcOEt=4:1-3:1)

Sources & evidence

ORD record
ord-83b9c8ced9294893adcb447fc35e1861
Source dataset
uspto-grants-2010_10
Patent number
US07812014B2

Reaction notes

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