Water → HCID 13649489, compound

Participants

Reaction Steps

A slurry of 881 g of 10,11-dihydro-5-H-pyrrolo-[2,1-c][1,4]benzodiazepin-11-one is stirred in 12 L of methylene chloride, and 819 g of 99% phosphorus oxychloride is added all at once. The mixture is stirred and refluxed for 19 hours. The reaction mixture is cooled to room temperature. A mixture of 5 L of crushed ice, 7.5 L of cold water and 1.81 kg of 28% ammonium hydroxide solution is stirred and 1.25 L portions of the reaction mixture are added over a period of 15 minutes. The reaction temperature is kept below 25° during the addition. After stirring for 15 minutes, the layers are separated, the methylene chloride layer is washed by stirring with 1 L of cold water then dried by stirring with magnesium sulfate for 1 hour. Charcoal (90 g) is added and the mixture is filtered through filter-cel. The methylene chloride solution is concentrated to dryness in vacuo to give 11-chloro-5H-pyrrolo[2,1-c][1,4]benzodiazepine, m.p. 102°-104°.

Provenance & Evidence