Uses
5-Chloro-2-(methylamino)benzophenone is an impurity of 1,4- Temazepam (T017200) as well as a decompoition product of Diazepam and other 1,4-benzodiazepine derivatives.
Synthesis
Weigh 231g of 2-amino-5-chlorobenzophenone, 900g of dimethyl carbonate and 70g of NaY molecular sieves with high silica-aluminum ratio and small grain NaY molecular sieves in a reaction flask. Stirred and heated up to 80C. After holding the reaction for 8h, a sample was taken and analyzed, and the content of raw material 2-amino-5-chlorobenzophenone in the reaction solution was measured to be 0.2%, and the reaction could be stopped.
Pass water cooling to room temperature, filtration to remove the catalyst, the filtrate is transferred to a reduced-pressure steaming flask, the unreacted dimethyl carbonate evaporated under reduced pressure, the residue is recrystallized with ethanol to obtain yellow needle crystals, that is, 221g of 2-methylamino-5-chlorobenzophenone, 90.2% yield, melting point of 94.0-95.1 C, HPLC purity of 98.9%.
