5-chloro-2-isocyanatobenzonitrile

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The intermediate prepared from 2-isocyanato-5-chlorobenzonitrile (6.1 g) and 4-hydroxybenzoylhydrazine (7.0 g) in 53% yield as described in Example 23 is added to a mixture of triethylamine (31 ml), methanesulphonic acid (25 drops) and ethanol (300 ml) and stirred at reflux under nitrogen for two hours. The reaction mixture is concentrated to dryness at reduced pressure, redissolved in ethanol and treated with water. The solid is collected, washed with water and dried under high vacuum to afford pure 9-chloro-2-(4-hydroxy-phenyl)-[1,2,4]triazolo[1,5-c]quinazolin-5(6H)one, mp>350° at reflux under nitrogen for two hours The reaction mixture is concentrated to dryness at reduced pressure redissolved in ethanol treated with water The solid is collected washed with water dried under high vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The intermediate prepared from 2-isocyanato-5-chlorobenzonitrile (6.1 g) and 4-hydroxybenzoylhydrazine (7.0 g) in 53% yield as described in Example 23 is added to a mixture of triethylamine (31 ml), methanesulphonic acid (25 drops) and ethanol (300 ml) and stirred at reflux under nitrogen for two hours. The reaction mixture is concentrated to dryness at reduced pressure, redissolved in ethanol and treated with water. The solid is collected, washed with water and dried under high vacuum to afford pure 9-chloro-2-(4-hydroxy-phenyl)-[1,2,4]triazolo[1,5-c]quinazolin-5(6H)one, mp>350° at reflux under nitrogen for two hours The reaction mixture is concentrated to dryness at reduced pressure redissolved in ethanol treated with water The solid is collected washed with water dried under high vacuum