摘要:
Described are preferred processes for producing extrusion-granulated supernucleophilic 4-amino-substituted pyridine catalysts, and granular products obtainable therefrom. Also described are preferred activation-substitution-deactivation processes for producing 4-aminopyridine compounds, which involve the use of acrylic acid or acrylamide or analogs thereof for activation, and substitution steps conducted under mild basic conditions in an excess of the amine reagent for 4-substitution. Such processes provide improved reacted masses which are more readily processed to recover the products in pure, heat-stable form. Further, described are processes for preparing 4-substituted-pyridines via pyridine betaines.
摘要:
Processes for preparing a 4-(secondary or tertiary)aminopyridine are provided. The processes comprise reacting a 4-substituted pyridine base having a leaving group as the 4-substituent, with an activating agent so as to form a corresponding 1,4-substituted pyridine; reacting the 1,4-substituted pyridine with a primary or secondary amine to substitute an amino group at the 4-position, and thereby form a corresponding 1-substituted-4-(secondary or tertiary) aminopyridine, wherein the reacting is conducted in a substitution reaction medium essentially free from strong base; and treating the 1-substituted-4-aminopyridine compound to remove the 1-substituent and thereby form a product medium including the 4-(secondary or tertiary) amino-pyridine.
摘要:
Described are preferred processes for producing extrusion-granulated supernucleophilic 4-amino-substituted pyridine catalysts, and granular products obtainable thereform. Also described are preferred activation-substitution-deactivation processes for producing 4-aminopyridine compounds, which involve the use of acrylic acid or acrylamide or analogs thereof for activation, and substitution steps conducted under mild basic conditions in an excess of the amine reagent for 4-substitution. Such processes provide improved reacted masses which are more readily processed to recover the products in pure, heat-stable form. Further, described are processes for preparing 4-substituted-pyridines via pyridine betaines.
摘要:
Methods are provided for improving production of 3,5-diethyl-1,2-dihydro-1-phenyl-2-propylpyridine (DHP). In one illustrative embodiment, the methods involve controlling the rate of reaction and temperature of the reaction during formation of DHP. In another illustrative embodiment, the methods involve neutralizing the acid catalyst subsequent to DHP formation.
摘要:
Described are preferred processes for preparing 3,5-dichloropyridines by dechlorinating higher-chlorinated pyridine compounds such as 2,3,5,6-tetrachloropyridine in an acidic medium in the presence of zinc and optionally a quaternary ammonium catalyst.