N-benzylhydroxylamine

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: An etheral solution (1 ml) of 2-methyl-3-tetrahydropyranyloxypropanal (37.9 mg; 0.20 mmol) was added dropwise to a suspension of benzylhydroxylamine (28.7 mg; 0.23 mmol) and powdery calcium chloride (22.2 mg; 0.20 mmol) in ether (0.5 ml) at 0° C., and the resultant mixture was stirred for 1.5 hours. The reaction mixture was purified by TLC using ethyl acetate to give N-(2-methyl-3-tetrahydropyranyloxypropylidene)-benzylamine-N-oxide (34.9 mg; yield, 57%). The reaction mixture was purified by TLC

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixture of N-benzylhydroxylamine prepared by the method as described in J. Am. Chem. Soc., 93, 2897 (1971) (368 mg; 3.0 mmol) and calcium chloride (3.30 mg; 3.0 mmol), anhydrous ether (30 ml) was added in argon stream, and (S)-(+)-3-(t-butyldimethylsilyloxy)-2-methylpropanal (600 mg; 3.0 mmol) was added dropwise thereto at 0° C. Stirring was continued at the same temperature for 1 hour and then at room temperature for 2 hours. The reaction mixture was filtered, and the filtrate was distilled under reduced pressure to remove the solvent. The oily residue was purified by silica gel column chromatography using a mixture of hexane and ethyl acetate (5:5-0:10) to give (R)-(-)-N-(3-t-butyldimethylsilyloxy-2-methylpropylidene)benzylamine-N-oxide (658 mg; 64%). prepared by the method was added dropwise at 0° C at room temperature for 2 hours The reaction mixture was filtered the filtrate was distilled under reduced pressure to remove the solvent The oily residue was purified by silica gel column chromatography a mixture of hexane and ethyl acetate (5:5-0:10)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 1.28 g (4 mmoles) of N-benzyl-N-mesyl-O-(p-methoxybenzylhydroxylamine prepared as described in Example 1 was treated with 15 ml of a 38% hydrogen bromide solution in acetic acid at room temperature for 20 hours in the presence of 1.5 g of phenol, and the mixture was then concentrated under a reduced pressure. 30 ml of diethyl ether and 10 ml of water and were then added to the resulting residue, and the aqueous layer was separated, concentrated under a reduced pressure to a small volume, adjusted to a pH of 8 with sodium carbonate and allowed to stand for 5 hours in a refrigerator. The crystals precipitated were collected by filtration to obtain 0.15 g (33% yield) of N-benzylhydroxylamine having a melting point of 56°-57° C. (The melting point reported in the literature is 57° C). the mixture was then concentrated under a reduced pressure 30 ml of diethyl ether and 10 ml of water and were then added to the resulting residue the aqueous layer was separated concentrated under a reduced pressure to a small volume The crystals precipitated were collected by filtration

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