4-Nitrobenzyl bromide → N-(t-butyldimethylsilyl)-4-[3-(p-nitrobenzyloxycarbonyl)-2-hydroxypropyl]-azetidin-2-one

HRID 2295324Notes

Reaction equation

HRID 2295324 reaction equation
[Si:1]([N:8]1[CH:11]([CH2:12][CH:13]([OH:18])[CH2:14][C:15]([OH:17])=[O:16])[CH2:10][C:9]1=[O:19])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[N+:20]([C:23]1[CH:30]=[CH:29][C:26]([CH2:27]Br)=[CH:25][CH:24]=1)([O-:22])=[O:21]>C(N(CC)CC)C>[Si:1]([N:8]1[CH:11]([CH2:12][CH:13]([OH:18])[CH2:14][C:15]([O:17][CH2:27][C:26]2[CH:29]=[CH:30][C:23]([N+:20]([O-:22])=[O:21])=[CH:24][CH:25]=2)=[O:16])[CH2:10][C:9]1=[O:19])([C:4]([CH3:6])([CH3:7])[CH3:5])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 660114-Nitrobenzyl bromideHCID 15136308N-(t-butyldimethylsilyl)-4-(3-carboxy-2-hydroxypropyl)-azetidin-2-one

Product 1

HCID 12848994N-(t-butyldimethylsilyl)-4-[3-(p-nitrobenzyloxycarbonyl)-2-hydroxypropyl]-azetidin-2-one

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Procedure

The crude carboxylic acid is suspended in anhydrous acetonitrite (150 ml) and treated with p-nitrobenzyl bromide (7.56 g, 35 mμol) and triethylamine (4.9 ml, 35 mμol). The resulting solution is kept at room temperature for 2 days and then in a refrigerator for 3 days. The reddish orange solution is evaporated under vacuum and the residue shaken with ethyl acetate (100 ml, 2×50 ml) and filtered to remove triethylammonium bromide. The ethyl acetate filtrate is washed with water (3×100 ml) and brine, dried with magnesium sulfate, filtered, and evaporated under vacuum to an amber oil (13.62 g). Crystallization from diethyl ether affords N-(t-butyldimethylsilyl)-4-[3-(p-nitrobenzyloxycarbonyl)-2-hydroxypropyl]-azetidin-2-one (6.84 g) as an off-white powder. Chromatography of the mother liquors on a silica gel column using 1:1 toluene-ethyl acetate as eluting solvent affords addition product (3.14 g) as an oil which solidifies.

Workup

  1. waitin a refrigerator for 3 days
  2. customThe reddish orange solution is evaporated under vacuum
  3. filtrationfiltered
  4. customto remove triethylammonium bromide
  5. washThe ethyl acetate filtrate is washed with water (3×100 ml) and brine
  6. dry with materialdried with magnesium sulfate
  7. filtrationfiltered
  8. customevaporated under vacuum to an amber oil (13.62 g)
  9. customCrystallization from diethyl ether

Sources & evidence

ORD record
ord-7d2870f14030442f83566418fe1619ce
Source dataset
uspto-grants-1984_01
Patent number
US04424230

Reaction notes

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