Phosphorus pentachloride → HCID 21315972, compound

Participants

Reaction Steps

A 4.0 g. portion of 3-chlorothieno[3,4-b][1,5]benzoxazepin-10(9H)-one (Example 12) and 4.0 g. of phosphorus pentachloride in 103 ml. of dry toluene is refluxed for 41/2 hours. The reaction temperature is concentrated, then is triturated with toluene to give 3,10-dichlorothieno[3,4-b][1,5]benzoxazepine. A 25 ml. amount of dry N-(2-hydroxyethyl)piperazine and 25 ml of dry toluene is added to the product above and the mixture is heated at 120° C. for 16 hours. The reaction mixture is concentrated to a thick oil, the oil is dissolved in hot 2N aqueous acetic acid, treated with activated charcoal and filtered through diatomaceous earth. The filtrate is cooled and precipitated with concentrated ammonium hydroxide. The precipitate is collected and extracted into methylene chloride, the organic solution is dried over anhydrous sodium sulfate and eluted through magnesium silicate with 2.5 liters of methylene chloride followed by one liter of 1:1 ethyl acetate:methylene chloride. The combined organic solvents are evaporated to yield 2.0 g. of 4-(3-chlorothieno[3,4-b][1,5]-benzoxazepin-10-yl)-1-piperazineethanol.

Provenance & Evidence