tert-butyl N-hydroxycarbamate

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

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

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

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

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

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

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: A solution of 3 g of (4-bromo-phenyl)-(2-methyl-4-methoxyphenyl)-methanone (prepared from 3-methylanisole and 4-bromobenzoyl chloride by Friedel-Crafts reaction analogously to Ex. 14a) in 100 ml of tetrachloromethane is treated with 2.1 g of N-bromosuccinimide and a spatula tip of dibenzoyl peroxide. The reaction mixture is stirred at room temperature for 6 hrs. under irradiation, subsequently diluted with 100 ml of methylene chloride and washed in succession with saturated sodium hydrogen carbonate solution and saturated sodium chloride solution. The organic phase is dried, filtered and immediately reacted. The solution is added dropwise to a mixture, previously stirred at 0° C., of 2.13 g of tert-butyl N-hydroxy-carbamate and 0.38 g of sodium hydride in 30 ml of TMF. The reaction mixture is warmed to room temperature and stirred. For the working-up, the mixture is treated with 60 ml of saturated ammonium chloride solution and the separated organic phase is washed with saturated sodium chloride solution, dried over sodium sulphate and concentrated. After chromatography of the residue (silica gel, ethyl acetate-hexane, 10:90 to 25:75) there are obtained 2.65 g of tert-butyl [2-(4-bromo-benzoyl)-5-methoxy-benzyloxy]-carbamate, MS: m/e 436 (M+H+, 1 Br). under irradiation washed in succession with saturated sodium hydrogen carbonate solution and saturated sodium chloride solution The organic phase is dried filtered immediately reacted The solution is added dropwise to a mixture The reaction mixture is warmed to room temperature stirred the separated organic phase is washed with saturated sodium chloride solution dried over sodium sulphate concentrated

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

Procedure: Boc anhydride (5.91 g, 0.026 mole) was added in one portion to a stirred solution of amino alcohol in anhydrous DCM (150 mL), and the reaction mixture stirred at ambient temperature under argon for 4.5 h. Water (200 mL) was added to the reaction mixture and the organic layer separated. The organic layer was washed with brine (100 mL), dried (Na2SO4), filtered, and concentrated to give N-boc amino alcohol as a colorless liquid that became a colorless glass upon standing. The material was used without further purification. Yield: 9.0 g (quantitative); LCMS: (+) ESI: m/z=368 [M+Na]+. the organic layer separated The organic layer was washed with brine (100 mL) dried (Na2SO4) filtered concentrated

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

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

Procedure: A stirred solution of t-butyl-N-hydroxycarbamate (0.25 g) in ethanol (10 ml) was treated with postassium hydroxide (0.10 g), then diethyl 3-bromo-3(1-trityl-1,2,4-triazol-3-yl)propane phosphonate (1.0 g, prepared as described in Example 29) added. The mixture was allowed to stand for twenty hours, poured into ice-water, neutralized with a little acetic acid and extracted with ethyl acetate. The extracts were washed with brine, dried over magnesium sulphate, and evaporated under reduced pressure to give crude diethyl 3-t-butoxycarbonylaminoxy-3(1-trityl-1,2,4-triazol-3-yl)propane phosphonate (1.14 g) as a colourless gum. NMR (CDCl3): δ 1.3(6H,t), 1.4(9H,s), 1.5-1.8(2H,m), 2.2-2.3(2H,m), 4.1(4H,m), 5.0(1H,t), 7.1(6H,m), 7.3(9H,m), 7.95(1H,s). M/S: M+ 620. to stand for twenty hours extracted with ethyl acetate The extracts were washed with brine dried over magnesium sulphate evaporated under reduced pressure