Y-Aminopyridine

SYNS AMINO-4-PYRIDINE y-AMINOPYRIDINE p-AMINOPYRIDINE 4-AP AVITROL 4-PYRIDINAMINE 4-PYRIDYLAMINE RCRA WASTE NUMBER POOS VMI 10-3... 

AMINOPYRIDINE see AMIOOO p-AMINOPYRIDINE see AMI500 m-AMINOPYRIDINE (DOT see AMI250 a-AMINOPYRIDINE see AMIOOO Y-AMINOPYRIDINE see AMI500... 

The first amination of a halogenopyridine involving a rearrangement was carried out by Levine and Leake in 1955 in an attempt to prepare 3-phenacylpyridine. When 3-bromopyridine (27, X = Br) was allowed to react with sodium amide in liquid ammonia in the presence of sodio-acetophenone, the reaction mixture obtained consisted chiefly of amorphous nitrogenous material from which only 10% of 4-aminopyridine (34, Y = NH2) and 13.5% of 4-phenacylpyridine were isolated. 

Amination of the various four 2-halogenopyridines (24, X = F, Cl, Br, I) under analogous conditions gave 2-aminopyridine (25, Y = NH2) as the sole reaction product in greater than 85% yield.The mechanism of these reactions is discussed in Section II, A, 3. 

Aminopyridines or Pyr idylamines(loimet y called Pyridonimides), Cs HsNa, mw 94.11,... 

Reaction of 2 equiv of 2-aminopyridines with 2-hydropolyfluoroalk-2-anoates 351 in MeCN in the presence of NEt3 at 90 °C for 50 h afforded a mixture of the isomeric 2-oxo-2H- and 4-oxo-4f/-pyrido[l,2-a]pyrimidines 110 and 111. Reaction of 3 equiv of 2-amino-pyridines and 2-hydropoly-fluoroalk-2-enoates 351 in MeCN in the presence K2C03 could be accelerated by ultrasonic irradiation (125 W). 2-Amino-6-methylpyridine yielded only 2-substituted 6-mcthyl-4//-pyrido[l,2-a]pyrimidin-4-oncs 111 (R = 6-Me), whereas 2-amino-5-bromopyridine gave a mixture of 7-bromo-4//-p y ri d o [ 1,2 - a ] p y ri m i d i n -4- o n c (111, R = 7-Br, Rf = CF2C1) and 2-(chlor-o,difluoromethyl)-6-bromoimidazo[l, 2-<2]pyrimidine-3-carboxylate in 44 and 8% yields, respectively (97JCS(P1)981). Reactions in the presence of K2C03 in MeCN at 90°C for 60h afforded only imidazo[l,2-a]pyrimidine-3-carboxylates. 

From the reaction mixture of 2-aminopyridine and perfluoro-2-methylpent-2-ene in MeCN a 9 1 mixture of 2,4-difluoro-2-penta-fluoroeth y 1 - 3-trill u o ro met hyl-4/7- and isomeric 2,4-difluoro-4-penta-fluoroeth i-3-trilluoromethyl-2//-pyrido[l, 2-a]pyrimidine (64%), and 2-pentafluoroethyl-3-trifluoromethyl-4//-pyrido[l, 2-a]pyrimidine-4-one (20%) was isolated (00JFC105). 

Reaction of 2-aminopyridine with ethyl 2-cyano-3-ethoxy-3-methyl-, -3-ethyl-, -3-phenylacrylates and ethyl 2-ethoxycarbonyl-3-ethoxy-3-methyl-, -3-phenylacrylates in boiling xylene yielded 2-substituted 4//-pyrido[l,2-Similar reactions of 2-aminopyridine with 2-cyano-3-ethoxyacrylonitrile and its 3-methyl, 3-ethyl, -3-phenyl derivatives in boiling MeCN afforded 4-imino-4/7-pyrido[l,2-a]-pyrimidine-3-carbonitrile and its 2-substituted derivatives. 

Compound (1) and 2-methyl-1//-pyrrolo[2,3-Z>]pyridine (87) have been prepared by a heterogeneous catalyzed Fischer reaction. A cyclization reaction occurred with acetaldehyde and acetone 2-pyridylhydrazones in the presence of y-alumina and fluorinated aluminum oxide (Equation (20)). In addition to the desired pyrrolopyridine products, 2-aminopyridine (88) and a triazine derivative (89) were also formed. Use of the fluorinated aluminum oxide maximized formation of the desired products <72CHE594, 72CHE1037). 

In Equation 4.4, ymm is the minimum y value of the curve, ymax is the maximum y value of the curve, cone, is the test concentration, and n is the Hill slope of the curve. We found that the Kv. 3 current was sensitive to inhibition by the Stichodactyla helianthus peptide, ShK, as well as ShK-Dap22, charybdotoxin (all pre-dissolved in water, with 0.1% BSA present during the experiment), and 4-aminopyridine (4-AP), which was dissolved directly in D-PBS (Figure 4.6A). 

Tu S, Jiang B, Zhang Y et al (2007) An efficient and chemoselective synthesis of iV-sub-stituted 2-aminopyridines via a microwave-assisted multi-component reaction. Org Biomol Chem 5 355-359... 

---