N,N-dibenzylhydroxylamine

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:0.01; pressure:0.00; stir:; reaction started in ice bath before addition of pivaloyl chloride, then allowed to warm to 23 C, then stirred for ' an additional 6 hours at RT (23 degC)

実験手順: 3 x 50 mL DCM extraction in 1 L separatory funnel rotary evaporator (30 degC, 80 mmHg) Aluminum oxide (neutral, powder, reagent-grade) was purchased from J.T. Baker. The crude reaction mixture is suspended in dichloromethane (50 mL) and is loaded onto a column, with interior diameter of roughly 2 inches, packed with alumina (100 g) and wetted with hexanes. dichloromethane is used as the eluent, and fractions are collected in Erlenmeyer flasks (50 mL each). The desired product typically elutes in fractions 2 through 25. The fractions that contain the desired product are combined rotary evaporator (30 degC, 80 mmHg)

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: Dibenzylamine (3.0 g, 0.0152 mole) was added with ethyl acetate (15 ml) and anhydrous magnesium sulfate (3 g), and the mixture was stirred under ice cooling. A solution of methyltrioxorhenium (0.0114 g, 0.0457 mmole) dissolved in 35% aqueous hydrogen peroxide (1.8 g, 0.018 mole) was added dropwise to the mixture over 1 hour so as to keep internal temperature at 5° C. to 10° C. After the reaction mixture was stirred at the same temperature for 1 hour, the magnesium sulfate was removed by filtration, and the filtrate was added with a solution of oxalic acid (1.23 g, 0.0137 mole) dissolved in acetone (7 ml). The mixture was stirred for 30 minutes under ice cooling, and the precipitated crystals were collected by filtration to obtain oxalic acid salt of N,N-dibenzylhydroxylamine (3.0 g, yield: 65.2%) having melting point of 152-153° C. Chemical structure of the product was analyzed by 1H-NMR, mass spectrometry and elemental analysis. 1H-NMR (DMSO-D6) σ (ppm) (multiplicity, integrated value): 7.45-7.12 (m, 11H), 3.85 (s, 4H). Elemental analysis, calculated for C16H17N1O5 : C, 63.36; H, 5.65; N, 4.62, found: C, 63.30; H, 5.65; N, 4.62. was added dropwise to the mixture over 1 hour so as at 5° C. to 10° C After the reaction mixture was stirred at the same temperature for 1 hour the magnesium sulfate was removed by filtration The mixture was stirred for 30 minutes under ice cooling the precipitated crystals were collected by filtration

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

実験手順: U.S. Pat. No. 3,491,151 discloses a method for preparing N,N-dialkylhydroxylamine compounds by allowing hydroxylamines react with alkyl halides, alkyl tosylates or the like. However, this method is also undesirable, because it requires a prolonged reaction time and achieves a yield of no more than about 50%. Tetrahedron Letters, Vol. 37, No. 33 pp. 6025-6028, 1996 discloses a method for synthesizing nitrone compounds by oxidizing dibenzylamine by means of a combination of aqueous hydrogen peroxide and methyltrioxorhenium. According to this synthetic method, an N,N-dibenzylhydroxyl-amine compound is produced in addition to a nitrone compound as a major product. However, its yield is low. Furthermore, the method requires a large amount of methyltrioxorhenium. For these reasons, the method is only disadvantageously applied to practical preparations of N,N-dibenzylhydroxylamine compounds.

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

実験手順: A solution of 0.051 M dimethyldioxirane in acetone (32.9 ml, 1.67 mmol) was added to a cold stirred solution of N,N-dibenzylamine (Aldrich; 0.331 g, 1.67 mmol) in acetone (5 ml). The mixture was stirred for fifteen minutes in an ice bath. Evaporation of the solvent on the rotary evaporator gave a white crystalline solid. The solid was dissolved in acetone and the solution dried with anhydrous Na2SO4. The solvent was removed to give a chromatographically homogeneous white solid (0.352 g, 98% yield). Measured mp was 121-122; reported mp is 122-123 (DeLaMare et al 1963). Evaporation of the solvent on the rotary evaporator gave a white crystalline solid the solution dried with anhydrous Na2SO4 The solvent was removed

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

実験手順: The procedure of Example 1 is repeated using 10.66 g (50 mmol) of N,N-dibenzylhydroxylamine and 5.56 g (25 mmole) of 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate. The residue is recrystallized from a 1:1 heptane: toluene solvent mixture to give 11.0 g (68%) of a white soldi, m.p. 139°-146° C. The residue is recrystallized from a 1:1 heptane toluene solvent mixture to give 11.0 g (68%) of a white soldi, m.p. 139°-146° C.

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

実験手順: A stirred suspension of 10.70 g of N,N-dibenzylhydroxylamine in 25 ml of methanol is admixed dropwise with a solution of 4.53 ml conc. hydrochloric acid in 10 ml of water. A solution of 4.06 g of potassium cyanate in 15 ml of water is then added and the resulting suspension is stirred at room temperature for 3 hours. The crude product is removed by filtration and further purified by liquid chromatography to afford the title compound as a white solid; m.p. 127°-29° C. The crude product is removed by filtration further purified by liquid chromatography

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

実験手順: The procedure of Example I is repeated using 23.31 g of dibenzylhydroxylamine, 1.23 g of potassium-tert-butoxide and 20.0 g of N-tert-octylacrylamide in 100 ml of dry tetrahydrofuran to afford the title compound as a white crystalline solid: mp 96°-98° C.

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

実験手順: A solution of 21.33 g of dibenzylhydroxylamine in 100 ml of dry tetrahydrofuran is admixed with 1.12 g of potassium-tert-butoxide followed by 12.70 g of N-tert-butylacrylamide. The solution is heated under reflux for 24 hours under N2. The crude reaction mixture is concentrated under reduced pressure and the residue is partitioned between water and methylene chloride. The organic layer is washed with water, brine dried (MgSO4) and evaporated under reduced pressure. Purification by liquid chromatography affords the title compound as an oil. The solution is heated under reflux for 24 hours under N2 The crude reaction mixture is concentrated under reduced pressure the residue is partitioned between water and methylene chloride The organic layer is washed with water, brine dried (MgSO4) evaporated under reduced pressure Purification by liquid chromatography