O-Methylhydroxylamine hydrochloride → N-Benzyloxycarbonyl-2(R,S)-methoxyiminomethyl-3,4-dihydro-2H-1,4-benzoxazine
反応式
Cl.[CH3:2][O:3][NH2:4].[CH2:5]([O:12][C:13]([N:15]1[C:20]2[CH:21]=[CH:22][CH:23]=[CH:24][C:19]=2[O:18][CH:17]([CH:25]=O)[CH2:16]1)=[O:14])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1>N1C=CC=CC=1>[CH2:5]([O:12][C:13]([N:15]1[C:20]2[CH:21]=[CH:22][CH:23]=[CH:24][C:19]=2[O:18][CH:17]([CH:25]=[N:4][O:3][CH3:2])[CH2:16]1)=[O:14])[C:6]1[CH:7]=[CH:8][CH:9]=[CH:10][CH:11]=1参加物
4
実験手順
3.42 g of O-methylhydroxylamine hydrochloride are added to a solution of 600 mg of N-benzyloxycarbonyl-2(R,S)-formyl-3,4-dihydro-2H-1,4-benzoxazine (Rf =0.31; prepared by means of Swern oxidation (Example 1g) from Example 87c) in 30 ml of pyridine and the reaction mixture is then stirred at room temperature for 36 h and subsequently concentrated. The crude product is dissolved in ethyl acetate and the solution is washed with a 1N sodium bicarbonate solution, water and saturated sodium chloride solution. N-Benzyloxycarbonyl-2(R,S)-methoxyiminomethyl-3,4-dihydro-2H-1,4-benzoxazine is obtained (540 mg): Rf (A)=0.61. A further reaction analogously to Example 87a) and purification of the crude product by means of FC over 50 g of silica gel (mobile phase N) gives 2(R,S)-methoxyiminomethyl-3,4-dihydro-2H-1,4-benzoxazine: Rf (A)=0.51.