Patent GB-822134-A (GB)
Title: Process for aminating nitrogen-containing heterocyclic compounds
Inventor: RUDNER BERNARD
IPC: C07D215/42
Filed: 1958-01-27
Abstract: Compounds containing one or more unsaturated heterocyclic rings having at least one annular tertiary nitrogen atom doubly bonded to an adjacent annular carbon atom bearing a hydrogen atom are aminated by reaction with chloramine, whereby the hydrogen atom on the said adjacent doubly bonded annular carbon atom is replaced by an amino group.  The chloramine may be diluted with an inert gas such as nitrogen and/or ammonia.  Temperatures may range from - 10 DEG  to 100 DEG  C. and pressures are preferably atmospheric.  If desired excess of heterocyclic starting material may function as solvent or, alternatively, unreactive solvents may be used, such as water, hexane, xylene, chlorobenzene, dioxane and dimethylformamide.  The major proportion of the a -amino-product is in the form of the hydrochloride, the remainder being in the form of the free base.  The products may be recovered by crystallization, distillation, solvent extraction or by acylation with acetic anhydride or benzene sulphonyl chloride, and subsequent hydrolysis of the separated acylated product. Specified reactants are pyridine, quinoline, isoquinoline, 2 : 4 - lutidine, 8 - hydroxy-quinoline (as ammonium salt), 8-hydroxy-quinoline - 5 - sulphonic acid (as ammonium salt), a  - and g  - picolines, nicotinic acid, nicotinamide, pyridoxin, nikethamide, 2-, 3-and 4-vinylpyridine, halopyridines, dipyridyl, 5 : 6 : 7 : 8 - tetrahydroquinoline, 4 - benzyliso-quinoline, oxazoles, thiazoles, diazoles, diazines, triazines and purines. N-imino derivatives <FORM:0822134/IV (a)/1> and N-amino derivatives <FORM:0822134/IV (a)/2> are formed as by-products as well as a -amino compounds in which the amino group is attached to the singly bonded carbon atom adjacent to the ring nitrogen atom.  In examples pyridine is aminated to give a mixture comprising 2 - aminopyridinehydrochloride, 2 - aminopyridine and 1 - aminopyridinium chloride which was reacted with acetic anhyhydride or benzene sulphonyl chloride to isolate 2 - acetylaminopyridine or 2 - benzene-sulphonamidopyridine for subsequent hydrolysis, pyridine - benzenesulphonylimine being obtained as a by-product in the latter case; quinoline is aminated to give a mixture comprising 2-aminoquinoline and the hydrochloride thereof; isoquinoline is aminated to give a mixture comprising 1 - aminoisoquinoline, 3-aminoisoquinoline, 1 - aminoquinoline hydrochloride and 2 - aminoisoquinolinium chloride (identified by reaction with sodium picrate and potassium hexafluorophosphate, respectively); 2 : 4-lutidine is aminated to give a mixture comprising 2 - amino - 4 : 6 - lutidine, 2 - amino - 4 : 6 - lutidine hydrochloride, 2 : 4 - lutidine-1-imine (identified by reaction with HCl and KPF6, respectively) and 1-amino-2 : 4-lutidinium chloride; the ammonium salt of 8-hydroxyquinoline is aminated to give a mixture comprising 2-amino-8-hydroxyquinoline (mainly as the ammonium salt) and 1-amino - 8 - hydroxyquinolinium betaine; the ammonium salt of 8-hydroxyquinoline-5-sulphonic acid is aminated to give a mixture comprising 2 - amino - 8 - hydroxy - 5 - sulphoquinoline hydrochloride and 1-amino-8-hydroxy-5-sulphoquinolinium betaine; a -picoline is aminated to give a mixture comprising 2-amino - 6 - methylpyridine and the hydrochloride thereof; g -picoline is aminated to give a mixture comprising 2-amino-4-methylpyridine and the hydrochloride thereof; and the ammonium salt of nicotinic acid is aminated to give 2-aminonicotinic acid.