反应详情

2-Chloro-5-fluoro nicotinic acid (3.00 g, 0.017 mol) (see Preparation 41), was dissolved in dichloromethane (100 ml) and N,N-dimethylformamide (1 drop) was added, followed by oxalyl chloride (3.0 ml, 0.034 mol). The reaction mixture was held at room temperature for 4 hours, after which time the solvent was removed in vacuo. The residue was suspended in dichloromethane (100 ml) and triethylamine (5 ml) added followed by addition of (4-amino-cyclohexyl)-carbamic acid tert-butyl ester (5.40 g, 0.026 mol) (Preparation 42a). The reaction mixture was then held under an atmosphere of nitrogen at room temperature for a further 18 hours. The reaction mixture was then washed with water (100 ml) and the organic phase dried over anhydrous magnesium sulphate. The solvent was removed in vacuo, and the residue triturated with ethyl acetate/pentane: (1:1, by volume, 10 ml) giving {4-[(2-chloro-5-fluoro-pyridine-3-carbonyl)amino]-cyclohexyl}-carbamic acid tert-butyl ester (2.5 g, 80:20 syn:anti) as a white solid.

1. customafter which time the solvent was removed in vacuo
2. additiontriethylamine (5 ml) added
3. waitThe reaction mixture was then held under an atmosphere of nitrogen at room temperature for a further 18 hours
4. washThe reaction mixture was then washed with water (100 ml)
5. dry with materialthe organic phase dried over anhydrous magnesium sulphate
6. customThe solvent was removed in vacuo
7. customthe residue triturated with ethyl acetate/pentane