As a common heterocyclic compound, it belong phthalazine compound,Phthalazin-1(2H)-one,119-39-1,Molecular formula: C8H6N2O,mainly used in chemical industry, its synthesis route is as follows.,119-39-1
A. Conventional Preparation of 1-Chlorophthalazine. One mole equivalent (10 g) of 1(2H)-phthalazinone and 7.7 mole equivalents (82.5 g, 50.1 mL) of phosphorus oxychloride were charged into a 100-mL, 3-necked flask fitted with a temperature probe and condenser. The slurry was stirred and heated to 70 C., and then the heat source was removed. The mixture was allowed to cool to room temperature, and then was poured in portions over 500 g of ice. After the initial addition of the reaction mixture, a violent exotherm was observed, and a portion of the solution spilled over the sides of the container. Ice quenching was completed with extreme caution but without further incident. Alternative workups were also examined. As a first alternative, after the reaction mixture reached room temperature, it was concentrated by heating at 45 C. under vacuum. The resulting yellow slurry was added in portions to 3 volumes of cold, deionized water. Once again, control of exothermic reactions that occurred during this quenching step was difficult. As a second alternative, after the reaction mixture reached room temperature, it was concentrated by heating at 45 C. under vacuum. To the resulting oily yellow paste was added 5 volumes of toluene, and the resulting biphasic solution was concentrated by heating at 45 C. under vacuum to remove the phosphorus oxychloridettoluene azeotrope. The process was repeated a second time. The resulting yellow paste solidified into an unworkable solid that was discarded. As a third alternative, after the reaction mixture reached room temperature, it was concentrated by heating at 45 C. under vacuum. To the resulting oily yellow paste was added 2 volumes of toluene, and the resulting biphasic solution was concentrated by heating at 45 C. under vacuum to remove the phosphorus oxychloride/toluene azeotrope. The process was repeated a second time, and then 2 volumes of tetrahydrofuran were added. The resulting slurry was stirred and cooled to 0 C. and then was filtered to isolate a light yellow solid. The filtrate was treated as described in the following paragraph. The aqueous mixture was rendered basic by the addition of 5 N sodium hydroxide solution. A light yellow precipitate formed. The solid was isolated by extraction into dichloromethane and concentration of the resulting extracts to dryness. A moist cake of 1-chlorophthalazine was thus obtained in yields that ranged from 80% to 440% of theoretical. If the moist cake was allowed to dry, or if this material was not used immediately, it darkened and underwent degradation to a mixture of the desired product, 1-chlorophthalazine, and multiple by-products. To prevent this loss and contamination, freshly obtained, moist chloro compound was used immediately.
With the synthetic route has been constantly updated, we look forward to future research findings about Phthalazin-1(2H)-one,belong phthalazine compound
Reference£º
Patent; Nelson, Deanna J.; US2005/137397; (2005); A1;,
Phthalazine – Wikipedia
Phthalazine | C8H6N2 – PubChem