| 摘要 |
Oxazolam drug intermediates 2 - amino - 5 - chlorine diphenyl ketone synthesis method , comprising the following steps: equipped with a stiffer, thermometer and a reflux condenser, the reaction vessel was added 3.51-3.55mol benzamide (2), the solution temperature was increased to 120-123 C, dropwise added 1.41 mol chloroaniline (3) , after the addition slowly heat up to 190--195 C, added 5.5-5.9mol stannous chloride, the solution temperature was increased to 240-250 C, the reaction at this temperature continued for 3-4h, until no gas generating, lowering the temperature of the solution to 90--95 C, 500ml potassium chloride solution was added, the temperature of the solution was raised to 130 C, reflux for 3-4h, the aqueous layer was decanted, the solution was cooled to precipitate a dark suspension, the suspension was added to 2.5 L phosphoric acid solution and refluxed for 20-23h, after cooling, the solution was poured into 1200ml sodium nitrate solution, the temperature of the solution is reduced to 5-8 , added cyclohexane solution for extraction, the cyclohexane solution layer was added 300ml sodium sulfite solution, distilled under reduced pressure, added acetonitrile solution to extract for 5-7 times, the precipitated solid was filtered, dehydrated with dehydrating agent, got yellow crystals2 - amino - 5 - chlorine diphenyl ketone . |
