Dimethylformamide → 7-(1-Hydroxy-1-p-bromophenacyloxycarbonylmethyl)-8-oxo-7-azabicyclo[4,2,0]oct-3-ene

HRID 1995716Notes

Reaction equation

HRID 1995716 reaction equation
[O:1]=[C:2]1[CH:9]2[CH:4]([CH2:5][CH:6]=[CH:7][CH2:8]2)[NH:3]1.O.[C:11]([OH:15])(=[O:14])[CH:12]=[O:13].[C:16](=[O:19])([O-])[O-].[K+].[K+].[Br:22][C:23]1[CH:28]=[CH:27][C:26](Br)=[CH:25][CH:24]=1.[CH3:30]N(C)C=O>CN(C)P(=O)(N(C)C)N(C)C.C(OCC)(=O)C>[OH:13][CH:12]([N:3]1[C:2](=[O:1])[CH:9]2[CH:4]1[CH2:5][CH:6]=[CH:7][CH2:8]2)[C:11]([O:15][CH2:30][C:16]([C:26]1[CH:27]=[CH:28][C:23]([Br:22])=[CH:24][CH:25]=1)=[O:19])=[O:14]

Participants

8

Reactant 5

HCID 6228Dimethylformamide2×HCID 78041,4-DibromobenzeneHCID 11430Potassium CarbonateHCID 3002787-Azabicyclo[4.2.0]oct-3-en-8-oneHCID 15620607Glyoxylic acid, monohydrate

Product 1

HCID 127969407-(1-Hydroxy-1-p-bromophenacyloxycarbonylmethyl)-8-oxo-7-azabicyclo[4,2,0]oct-3-ene

Reagents, catalysts & solvents 2

HCID 8857Ethyl AcetateSolventHCID 12679HexamethylphosphoramideSolvent2×

Procedure

The azetidinone (1) (0.4 g) in anhydrous dimethylformamide (2 ml) was stirred with glyoxylic acid hydrate (0.32 g) in the presence of hexamethylphosphorictriamide (0.1 ml) and molecular sieves (3A; 4 pieces) for 5 h. Potassium carbonate (0.226 g) was added, and the solution stirred until effervescence had ceased (5 min.). p-Bromophenylbromide (1.00 g; 1.05 equiv.) in dimethylformamide (1.0 ml) and hexamethylphosphorictriamide (0.25 ml) was added, and the solution stirred overnight. The solution was diluted with ethyl acetate, washed with saturated aqueous sodium chloride solution (×3), dried (Na2SO4) and evaporated to give a gum (1.9 g) which was chromatographed on Kieselgel. Elution of the column with ethyl acetate-petroleum ether (1:1) gave the glyoxylate ester (58). Isomer I as a foam, which slowly crystallised (ethyl acetate-petroleum ether) as needles (0.60 g), (47%) m.p. 135°-136°, νmax (CHCl3) 3250br, 1760sh, 1750, 1710, 1590, 970 cm-1 ; δ (d6DMSO) 1.9-2.8 (4H, m), 3.35 (1H, m), 4.17 (1H, m) 5.51 (1H, d, J 6.5 Hz; sharpens to a singlet on D2O exchange) 5.55 (2H, s, phenacyl CH2), 5.72br (2H, s), 6.81 (1H, d, J 6.5H, D2O exchangeable), 7.75 (2H, d, J 9 Hz) and 7.90 (2H, d, J 9 Hz) (Found: C, 51.9; H, 4.2; N, 3.6; Br, 20.00. C17H16BrNO5 requires C, 51.8; H, 4.1; N, 3.6; Br, 20.3%).

Workup

  1. custom(5 min.)
  2. stirringthe solution stirred overnight
  3. washwashed with saturated aqueous sodium chloride solution (×3)
  4. dry with materialdried (Na2SO4)
  5. customevaporated

Sources & evidence

ORD record
ord-75c92eac76504c86819056aeb7d3720a
Source dataset
uspto-grants-1983_09
Patent number
US04405637

Reaction notes

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