Potassium Hydroxide → 1-Methoxycarbonyl-3-oxopiperidine-4-carbohydroxamic acid ethylene acetal
Reaction equation
[OH-:1].[K+].[Cl-].O[NH3+:5].[CH2:6]1[O:24][C:9]([CH:13]2[CH2:18][CH2:17][N:16]([C:19]([O:21][CH3:22])=[O:20])[CH2:15][C:14]2=[O:23])(OCC)[O:8][CH2:7]1.[K+].[Br-]>CO.C(O)C.C(OCC)(=O)C.CO.C(O)=O.C(O)=O.C(OCC)(=O)C.C(O)(=O)C>[CH2:6]1[O:24][C:9]([CH:13]2[CH2:18][CH2:17][N:16]([C:19]([O:21][CH3:22])=[O:20])[CH2:15][C:14]2=[O:23])([NH:5][OH:1])[O:8][CH2:7]1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 6
Procedure
To a stirred and iced solution of potassium hydroxide (7.3 g; 130 mmol) in methanol (30 ml) was added hydroxylammonium chloride (6.9 g; 100 mmol). After stirring at 0° C. for further 30 minutes a solution of ethyl 1-methoxycarbonyl-3-oxopiperidine-4-carboxylate ethylene acetal (6.8 g; 25 mmol) in ethanol (20 ml) was added, and the mixture was left at 8° C. for 8 days. Upon addition of glacial acetic acid (15 ml) and filtration the filtrate was evaporated in vacuo to give a treacly mass. CC [silica gel (Woelm 0.063-0.1 mm): 250 g; eluents: ethyl acetate to which methanol (15-26%) and formic acid (1%) was added] afforded IXa (1.9 g; 29%) was a crystalline and TLC-pure substance [RF : 0.23; eluent: ethyl acetate-methanol-formic acid (90:9:1)]. An analytical sample was recrystallized (ethanol-benzene) to give IXa as colourless crystals, m.p. 150.0°-152.0° C. IR (KBr): 3700-3350 (m), 3280 (m), 3210 (s), 3055 (w), 3000-2870 (several bands, w-m), 1690 (s), 1640 (s), 1550 (w) cm-1. 1H NMR [CDCl3 -DMSO-d6 (1:1): δ10.5-10.1 (1H, m), 4.9-4.3 (1H, m), 3.93 (s), 3.60 (s), and 4.1-3.1 (m) (a total of 11H), 2.8-2.6 (1H, m), 2.2-1.8 (2H, m).
Workup
- additionwas added
- customwas evaporated in vacuo
- customto give a treacly mass
- customafforded IXa (1.9 g; 29%)
- customAn analytical sample was recrystallized (ethanol-benzene)
- customto give IXa as colourless crystals, m.p. 150.0°-152.0° C
Sources & evidence
- ORD record
- ord-2aaa1790558044c8a60b9d3dc3c1ba1a
- Source dataset
- uspto-grants-1981_07
- Patent number
- US04278676
Reaction notes
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