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

HRID 67930Notes

Reaction equation

HRID 67930 reaction equation
N1[CH2:4][CH2:3][C:2]1=O.[OH2:6].[C:7](O)(=O)[CH:8]=O.[C:12](=[O:15])([O-])[O-:13].[K+].[K+].[Br:18][C:19]1[CH:28]=[CH:27][C:22]([C:23](=[O:26])[CH2:24]Br)=[CH:21][CH:20]=1.[CH3:29][N:30]([CH3:33])[CH:31]=[O:32]>CN(C)P(=O)(N(C)C)N(C)C.C(OCC)(=O)C>[OH:32][CH:31]([N:30]1[C:33](=[O:6])[CH:8]2[CH:29]1[CH2:2][CH:3]=[CH:4][CH2:7]2)[C:12]([O:13][CH2:24][C:23]([C:22]1[CH:27]=[CH:28][C:19]([Br:18])=[CH:20][CH:21]=1)=[O:26])=[O:15]

Participants

8

Reactant 5

HCID 6228Dimethylformamide2×HCID 74544-Bromophenacyl bromideHCID 11430Potassium CarbonateHCID 1367212-AzetidinoneHCID 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 (28) (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-Bromophenacylbromide (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 (x 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 (30). 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 (x 3)
  4. dry with materialdried (Na2SO4)
  5. customevaporated

Sources & evidence

ORD record
ord-9ad8c6e8c2cd420ea68c8ee1378b371c
Source dataset
uspto-grants-1982_08
Patent number
US04347181

Reaction notes

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