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

HRID 1577868Notes

Reaction equation

HRID 1577868 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 5h. 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-7196ea4f1cc2460b8ee3773068021fbe
Source dataset
uspto-grants-1981_09
Patent number
US04289696

Reaction notes

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