m ph 7 was immediately added and the solution was adjusted to ph 7 7 5 with hydrochloric acid 1 n the title compound in solution was used as is to react with thiol reactive groups such as maleimides alkyl halides or thiols which are either free in solution or are coupled to proteins polypeptides or labels to a stirring solution of lorazepam 3 21 g 1 0 u00d7 10 2 mol in anhydrous dimethylformamide 100 ml was added anhydrous powdered potassium carbonate 1 52 g 1 1 u00d7 10 2 mol followed by iodomethane 0 69 ml 1 1 u00d7 10 2 mol the mixture was stirred at room temperature for 20 hours the solvent was evaporated under vacuum the residue was treated with water 100 ml and was stirred at room temperature for 2 hours the resulting fine light yellow solid was collected by filtration and was dried under vacuum to afford 3 3 g 98 of lormetazepam as a pale yellow solid m p 201 u00b0 203 u00b0 c lormetazepam 3 3 g 9 8 u00d7 10 3 mol was treated with thionyl chloride 40 ml 5 5 u00d7 10 1 mol and the resulting solution was refluxed with stirring for 1 hour the excess thionyl chloride was removed by addition of toluene 120 ml and distillation until the stillhead temperature reached 110 u00b0 c the solution was allowed to cool and the residual solvent was treated with methyl glycolate 8 ml 1 0 u00d7 10 1 mol and the mixture was stirred at 90 u00b0 c for 30 minutes when a red homogenous solution was obtained after cooling the excess methyl glycolate was evaporated under vacuum and the residue was treated.