4-(3-Azaniumylpropyl)morpholin-4-ium chloride hydrogen oxalate: an unusual example of a dication with different counter-anions

摘要

Methyl (2Z)-4-(1-benzofuran-2-yl)-2-hydroxy-4-oxobut-2-enoate (0.200 g, 0.816 mmol) was dissolved in 1,4-dioxane (5 ml). One molar equivalent of 4-(3-aminopropyl)morpho-line (0.816 mmol, 0.119 ml) was added to the 1,4-dioxane mixture, resulting in the formation of a yellow precipitate upon addition. One molar equivalent of 4-tert-butylbenz-aldehyde (0.816 mmol, 0.137 ml) was added to the mixture which was stirred at room temperature for 5 min. 4-(Benzo-furan-2-carbonyl)-5-(4-tert-butylphenyl) -3-hydroxy-1- [3- (mor-pholin-4-yl)propyl]-1H-pyrrol-2(5H)-one was isolated as a yellow powder (yield: 0.579 mmol, 0.291 g, 71%) and dried in vacuo. Subsequently, the dried powder (0.050 g, 0.093 mmol) was dissolved in dry methanol (2.5 ml).