4-Bromophenacyl bromide → 7-(1-Hydroxy-1-p-bromophenacyloxycarbonylmethyl)-8-oxo-7-azabicyclo[4,2,0]oct-3-ene
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(=O)([O-])[O-].[K+].[K+].[Br:22][C:23]1[CH:32]=[CH:31][C:26]([C:27](=[O:30])[CH2:28]Br)=[CH:25][CH:24]=1>CN(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][CH2:28][C:27]([C:26]1[CH:31]=[CH:32][C:23]([Br:22])=[CH:24][CH:25]=1)=[O:30])=[O:14]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 3
Procedure
The azetidinone (1) (0.4 g) in ahydrous 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 (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
- custom(5 min.)
- stirringthe solution stirred overnight
- washwashed with saturated aqueous sodium chloride solution (x 3)
- dry with materialdried (Na2SO4)
- customevaporated
Sources & evidence
- ORD record
- ord-99fac0e1f1a344a4ac5da0acb8bf22a7
- Source dataset
- uspto-grants-1984_02
- Patent number
- US04431587
Reaction notes
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