5- pyridin-2-amine

There is evidence from a detailed study of the photolyses of 2-alkyl-substituted aryl azides 40 in diethylamine that A3,7V-diethyl-1 //-azepin-2-amines are formed as oxygen-sensitive, meta-stablc intermediates that can give rise to a variety of byproducts, including 5-acyl- A%V-diethyl-pyridin-2-amines and 6-alkyl-7-(diethylamino)-2//-azepin-2-ones 11 however, formation of these oxidation products can be avoided by refluxing the photolysate mixture with methanol prior to exposure to oxygen, in which case practicable yields of the /V,/V-diethyl-3W-azepin-2-amines 41 result. 

B.K., Yu, S. and Hartman, G.D. (2004) Potent N-(l,3-thiazoyl-2-yl)pyridine-2-amine vascular endothelial growth factor receptor tyrosine kinase inhibitors with excellent pharmacokinetics and low affinity for the hERG ion channel. Journal of Medicinal Chemistry, 47, 6363-6372. 

A mixture of ethyl 4-[[3-(2-furanylmethyl)-3H-imidazo[4,5-b]pyridin-2-yl]amino]-l-piperidinecarboxylate and of a hydrobromic acid solution 48% in water was stirred and heated for 3 h at about 80°C. The reaction mixture was evaporated and the residue was dried, yielding the 3-(2-furanylmethyl)-N-(4-piperidinyl)-3H-imidazo[4,5-b]pyridin-2-amine dihydrobromide (crystallized from methanol). 

Other approaches to related bicyclic systems include the reaction of 1,3-dicarbonyl compounds with l-amino-2(l//)-pyridin-2-amines or -pyrimidin-2-amines (Scheme 14) (94JHC1157] and the oxidation of 2- or 4-pyrimidinyl ketone arylhydrazones to yield triazolo[l,5-a - or -ll,5-c]pyrimidinium salts (Scheme 15). In this reaction 2,4,4,6-... 

Hydrogenolytic ring opening of the 5-substituted 1,2,4-oxadiazole ring of 3-(l,2,4-oxadia-zol-3-yl)pyridin-2-amines 5 in the 3-position creates a C-N -C side chain in the form of an acylated amidine 6. In refluxing xylene this cyclizes with the amino group in the 2-position to yield pyrido[2,3-c/]pyrimidin-4-amines 7.9... 

Armnopyridine-3-( A -acetyl)carboxamidine (6, R = Me 1.78 g, 10 mmol), prepared by catalytic hydrogenation of 3-(5-methyl-l,2,4-oxadiazol-3-yl)pyridin-2-amine (5, R —Me),15 was refluxed in xylene (100 raL) with a H20 separator, until no more H20 was produced (8 h). After concentration the product... 

Aminopyrido[2,3-rf]pyrimidin-4(3/f)-one (25) has been synthesized by the ring rearrangement of 3-(l,3,4-oxadiazol-2-yl)pyridin-2-amine in refluxing formic acid. The C-N side chain in this example is actually a carbohydrazide originating from the 1,3,4-oxadiazole ring in acidic solution.65... 

The combination of two moles of a pyridinamine and two moles of carbon dioxide at elevated temperatures and high pressure yields 3-(2-pyridyl)pyrido[2,3-t/]pyrimidine-2,4(l f/,3/7)-diones.137 Thus, pyridin-2-amine and carbon dioxide at 8500 atm and 200 "C gave 3-(2-pyridyl)-pyrido[2,3-<2]pyrimidine-2,4(l //,3/7)-dione (R = H). 

An A -alkylated 5,7-dimethyl-3,4-dihydropyrido[2,3-(7]pyrimidin-8(7//)-one, obtained by ring closure of the appropriate A2-alkyl-4,6-dimethyl-3- [(ethoxycarbonyl)aminolmethyl pyridin-2-amine in acetic acid, is oxidized by manganese(IV) oxide 10 another example is the aromatization of 2-aryl-l,2-dihydropyrido[2,3-tf]pyrimidin-4(3/f)-ones by potassium permanganate in acetone.66... 

Intramolecular cyclization of 3-(acylhydrazino)pyridin-2-amines with polyphosphoric acid affords pyrido[2,3-c]-l, 2,4-triazines 7.144 This reaction is an extension of the Bischler synthesis of 1,2,4-benzotriazines.149... 

Dichloroazacyanines, which can be prepared from dialkyl cyanamides with phosgene imini-um chloride, cyclize with pyridin-2-amine to form 2,4-bis(dimethylamino)pyrido[1,2- ]-l,3,5-triazinium perchlorate in 75% yield.489... 

H-lmidazo[4,5-5]pyridin-2-amine, 1-methyl-6-phenyl- PhIP 1740, 1741, 1743, 1744,2095a, 2448, 2484a, 2601, 3265, 3300, 3714 ... 

Kinae et al. (2095a) reported that A-heterocyclic amines [2-amino-3-methylimidazo[4,5-/ quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-/ quinoline (MelQ), l-methyl-6-phenyl-l//-imidazo[4,5-/7]pyridin-2-amine (PhIP)] were produced in an incubated solution of D-glucose and several amino acids at much lower temperatures and longer time periods than those encountered in the cooking of various foodstuffs (beef, poultry, fish). Several A-heterocyclic amines not found in CSC were also generated. The generation of the A-heterocyclic amines, as measured by the Ames test (Salmonella typhimurium TA 98), increased in proportion to the conditions imposed 37°C (90 d), 50°C (30 d), 128°C (2 h)... 

Methyl-5-phenyl-2,4-imidazolidinedione 1-Methyl-6-phenylimidazo[4,5-b]pyridin-2-amine 2-[Methyl(phenylmethyl)amino]ethanol 4-Methyl-/ /-(phenylmethylene)aniline 3-Methyl-2-phenylmorpholine... 

In the synthesis of risperidone, one fragment B started from pyridin-2-amine and 4-acetyldihydrofuran-2(3//)-one. Suggest intermediate A and... 

Acetylene black-immobilized CuO hollow nanospheres (CuO/AB) can be used for the N-arylation of heterocycles (Kim et al 2009). This novel catalytic system was suitable for a variety of substrates, including the electron-rich aryl halides and A-heterocycles. Heteroarylamines such as pyridine-2-amine, pyridine-3-amine, and pyrimidin-2-amine also afforded the desired A-aryl heterocyclic amines. However, a high temperature (180°C) was required to achieve good conversions. 

Methyl-6- phenylimidazo[4,5- i] pyridin-2-amine PhIP CisHigNg 105650- 23-5 224.261 solid 327 ... 

This reaction was carried out under an atmosphere of air. 3-Phenylpropiolaldehyde (0.5 mmol), pyridin-2-amine(0.6mmol), AcOH (5mol%), Cul (5mol%), and bipy (10mol%) were stirred for 12 h in CH Cl (3mL) at room temperature. After reaction was complete, as monitored by TLC and (3C/MS analysis, the solvent was then removed, and the product was isolated by column chromatography (eluted with petroleum ether/ethyl acetate=2 1) to give a pure sample (80%, 88.8 mg). 

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