N-bromoacetamide

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10.8 g. of cis-propenylphosphonic acid is dissolved in 50 ml. of water and the pH of the solution is adjusted to 4.2 by the addition of 2.5 N sodium hydroxide. 13.8 g. of N-bromoacetamide is added and the suspension is stirred at room temperature. The reaction is complete when the N-bromoacetamide is in solution and the mixture is negative to starch-iodide paper. The solution is lyophilized and the residue is triturated several times with chloroform to give sodium (2-hydroxy-1-bromopropyl)-phosphonate. the residue is triturated several times with chloroform

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10.8 g. of cis-propenylphosphonic acid is dissolved in 50 ml. of water and the pH of the solution is adjusted to 4.2 by the addition of 2.5 N sodium hydroxide. 13.8 g. of N-bromoacetamide is added and the suspension is stirred at room temperature. The reaction is complete when the N-bromoacetamide is in solution and the mixture is negative to starch-iodide paper. The solution is lyophilized and the residue is triturated several times with chloroform to give sodium (2-hydroxy-1-bromopropyl)-phosphonate. the residue is triturated several times with chloroform

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: N-bromoacetamide (2.021 g, 14.65 mmol) was added to the AcOH (100 mL) suspension of (Z)-9-(triisopropylsilyloxy)-8,9-dihydro-7H-cyclohepta[b]pyridine (4.5597 g, 14.36 mmol) and LITHIUM ACETATE (3.79 g, 57.4 mmol) at rt under N2. The flask was wrapped with alumina foil and stirred at room temperature overnight. The reaction became a clear yellow solution. The solvent was evaporated via high vacuum. The crude was partitioned between water and ethyl acetate. Na2CO3 was added until no bubbling. The organic was separated and the aqueous was extract by ethyl acetate again. The combined organic layer was dried (Na2SO4), filtered and concentrated to give a tan oil (crude product: 6.37 g). The crude was used as it is. MS (ESI)[M+H+]=458.36. The solvent was evaporated via high vacuum The crude was partitioned between water and ethyl acetate Na2CO3 was added until no bubbling The organic was separated the aqueous was extract by ethyl acetate again The combined organic layer was dried (Na2SO4) filtered concentrated to give a tan oil (crude product: 6.37 g)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1-(Benzyloxycarbonyldiethylphosphono)methyl-3-azido-4-(methylthio)-2-azetidinone (0.44 g.) is dissolved in methanol (20 ml.) and treated with N-bromoacetamide (0.52 g.) for two hours. Sodium thiosulfate (10 ml.; 0.1N) is then added and the mixture is allowed to stir for five minutes. At the end of this time, the reaction mixture shows no positive reaction to starch iodide paper. The reaction mixture is saturated with sodium chloride and extracted with methylene chloride. The methylene chloride extract is dried and evaporated. The residue is chromatographed to afford 1-(benzyloxycarbonyldiethylphosphono)methyl-3-azido-4-methylsulfonyl-2-azetidinone. extracted with methylene chloride The methylene chloride extract is dried evaporated The residue is chromatographed

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1-(Benzyloxycarbonyldiethylphosphono)methyl-3-azido-4-(methylthio)-2-azetidinone (0.44 g.) is dissolved in methanol (20 ml.) and treated with N-bromoacetamide (0.52 g.) for two hours. Sodium thiosulfate (10 ml.; 0.1N) is then added and the mixture is allowed to stir for five minutes. At the end of this time, the reaction mixture shows no positive reaction to starch iodide paper. The reaction mixture is saturated with sodium chloride and extracted with methylene chloride. The methylene chloride extract is dried and evaporated. The residue is chromatographed to afford 1-(benzyloxycarbonyldiethylphosphono)methyl-3-azido-4-methylsulfonyl-2-azetidinone. extracted with methylene chloride The methylene chloride extract is dried evaporated The residue is chromatographed

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 800 mg of 24,24-difluoro-5β-cholestane-3α,25-diol (Va) in 32 ml of tert-butyl alcohol, 15 ml of water, 200 μl of 48% hydrobromic acid and 800 mg of N-bromoacetamide were added. After stirring at room temperature for 3 days, ethyl acetate was added to the reaction mixture, which was then washed sequentially with 0.5% aqueous sodium thiosulfate and saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the resulting residue was purified through a short column (5 g of silica gel) to produce 950 mg of a crude product. The product was recrystallized from ether/hexane to produce 4β-bromo-24,24-difluoro-25-hydroxy-5β-cholestan-3-one. was then washed sequentially with 0.5% aqueous sodium thiosulfate and saturated aqueous sodium chloride dried over anhydrous magnesium sulfate The solvent was distilled off the resulting residue was purified through a short column (5 g of silica gel) to produce 950 mg of a crude product The product was recrystallized from ether/hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 0.5 g. (0.002 mole) of 2-phenyl-5,6-dihydro-s-triazolo[5,1-a]isoquinoline and 0.28 g. (0.002 mole) of N-bromoacetamide in 10 ml. of carbon tetrachloride is refluxed for 5 hours. The crystalline precipitate which forms is filtered and dissolved in methylene chloride. The resulting solution is washed with sodium bicarbonate, then the solvent is evaporated off and the obtained residue recrystallized from ethyl acetate. Yield 79%. A mixture of 0.5 g The crystalline precipitate which forms is filtered dissolved in methylene chloride The resulting solution is washed with sodium bicarbonate the solvent is evaporated off the obtained residue recrystallized from ethyl acetate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 0.5 g. (0.002 mole) of 2-phenyl-5,6-dihydro-s-triazolo[5,1-a]isoquinoline and 0.28 g. (0.002 mole) of N-bromoacetamide in 10 ml. of carbon tetrachloride is refluxed for 5 hours. The crystalline precipitate which forms is filtered and dissolved in methylene chloride. The resulting solution is washed with sodium bicarbonate, then the solvent is evaporated off and the obtained residue recrystallized from ethyl acetate. Yield 79%. A mixture of 0.5 g The crystalline precipitate which forms is filtered dissolved in methylene chloride The resulting solution is washed with sodium bicarbonate the solvent is evaporated off the obtained residue recrystallized from ethyl acetate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10.8 g. of cis-propenylphosphonic acid is dissolved in 50 ml. of water and the pH of the solution is adjusted to 4.2 by the addition of 2.5 N sodium hydroxide. 13.8 g. of N-bromoacetamide is added and the suspension is stirred at room temperature. The reaction is complete when the N-bromoacetamide is in solution and the mixture is negative to starch-iodide paper. The solution is lyophilized and the residue is triturated several times with chloroform to give sodium (2-hydroxy-1-bromopropyl)-phosphonate. the residue is triturated several times with chloroform

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10.8 g. of cis-propenylphosphonic acid is dissolved in 50 ml. of water and the pH of the solution is adjusted to 4.2 by the addition of 2.5 N sodium hydroxide. 13.8 g. of N-bromoacetamide is added and the suspension is stirred at room temperature. The reaction is complete when the N-bromoacetamide is in solution and the mixture is negative to starch-iodide paper. The solution is lyophilized and the residue is triturated several times with chloroform to give sodium (2-hydroxy-1-bromopropyl)-phosphonate. the residue is triturated several times with chloroform