Methyl 2-pyridyl

Heating 4-oxo-4//-pyrido[l, 2-n]pyrimidine-3-diazonium tetrafluorobo-rate and its 8-methyl derivative in alcohol at 60-90 °C for 15 min to 5h gave alkyl 1-(2-pyridyl)- and 1-(4-methyl-2-pyridyl)-l//-1,2,3-triazole-4-carboxylates (00H(53)1793). 

Cyclization of methyl 2-[2-benzoyl-2-ethoxycarbonyl-l-vinyl)amino]-3-[(4-methyl-2-pyridyl)amino]acrylate (311) afforded the 3-amino-8-methyl-4//-pyrido[l,2-n]pyrimidin-4-one derivative 312 (97JHC1511). 

Recently, it has been reported that methyl 2-pyridyl sulphoxides (10) and related pyridyl derivatives (11) (see Schepie 25) are good phase transfer catalysts for SN2 reactions of various primary or secondary alkyl halides in a two-phase reaction system and for the alkylation of phenylacetonitrile or phenylacetone with alkyl halides in liquid-liquid two-... 

Carbonylation of methanol to acetic acid is fully discussed in Chapter 9. Another carbonylation process using a phosphine ligand to control the course of the reaction is a highly atom efficient route to the widely used monomer methyl methacrylate (Scheme 4.19). In this process the catalyst is based on palladium acetate and the phosphine ligand, bisphenyl(6-methyl-2-pyridyl) phosphine. This catalyst is remarkably (>99.5%) selective for the 2-carbonylation of propyne under the relatively mild conditions of <100 °C and 60 bar pressure. 

Reaction of [Ir(cod)Cl]2 with (6-methyl-2-pyridyl)methyl lithium yields the binuclear species [(cod)Ir(/i-CH2-py-6-Me-C, /V)]2, (401). The Ir centers in (401) are 3.5889(3) A apart, indicating little metal-metal interaction. Treatment of (401) with PPh2Et yields [(cod)Ir(PPh2Et)2(CH2-py-6Me)], which contains the monodentate, carbon-bound pyridylmethyl ligand. 

Spontaneous self assembly of a dinuclear triple helical complex is observed with linked bis-[4,5]-pineno-2,2 -bipyridines. Studies by electrospray mass spectrometry, CD and NMR determined that the major species in solution was a complex of Zn L = 2 3 stoichiometry with a triple helical structure and an enantiomerically pure homochiral configuration at the metal centers. The preference for the formation of one of the possible stereoisomers over the other is of interest.265 Another binuclear triple helical complex is formed from zinc addition to bis[5-(l-methyl-2-(6-methyl-2 -pyridyl)benzimidazolyl)]methane. Spectrophotometric titrations with a zinc solution... 

US patent 6,806,280, Polymorph of 5-[4-[2-( -methyl- (2-pyridyl)amino)ethoxy] benzyl]-thiazolidine-2,4-dione, maleic acid salt [117]. This invention discloses a polymorphic form of 5-[4-[2-(A-methyl-jV-(2-pyridyl)amino)cthoxy]benzyl]-thia-zolidine-2,4-dione, maleic acid salt. The polymorphic form is characterized by (i) an infrared spectrum containing peaks at 1763, 912, 856, and 709 cm-1 and/or... 

The Jacobs-Gould intramolecular cyclization of diethyl N-(6-methyl-2-pyridyl)amino-methylenemalonate to 3-ethoxycarbonyl-7-methyl-l,8-naphthyrid-4-one is another reaction ideally suited to microwave heating, although conductively heated equipment was employed for laboratory-scale experiments [45]. The product is a key intermediate in the synthesis of nalidixic acid, the first of the quinolone antibacterials. The process usually is conducted at temperatures of 200-250 °C and in high dilution, with heat transfer oils such as the eutectic mixture of diphenyl ether and biphenyl. However, it proceeded rapidly, predictably and controllably under solvent-free conditions. 

Scheme 14.13 Proposed mechanism for the hydrogenation of phenyl acetylene by [Pd(methyl 2-pyridyl ketone thiosemicarba-zonato)Cl] (29a).

The condensation of 2-amino-6-methylpyridine and EMME was carried out in methyl-phenyl-polysiloxanes at 90-100°C to give high-purity (99%) diethyl A-(6-methyl-2-pyridyl)aminomethylenemalonate in 97% yield (84GEP3308089). 3-Amino-5-(pyridyl)-2-(17/)-pyridones were reacted with dialkyl alkoxymethylenemalonates in boiling ethanol for 6.0-6.5 h to... 

A mixture of 2-amino-6-methylpyridine, ethyl orthoformate, and diethyl malonate was heated at 150°C for 1 hr to give A-(6-methyl-2-pyridyl)-aminomethylenemalonate (262, R = 6-Me, R1 = Et) in 77% yield [74JAP(K)88879],... 

In the uncatalyzed condensations of 2-aminopyridines, alkyl orthoformate, and dialkyl malonate at 110°C, 2-pyridylaminomethylenemalona-mates (263, R = H, Me R1 = Me, Et) were obtained in 20-25% yields. When isoamyl orthoformate was applied, a 5.2 4.8 mixture of ethyl and isoamyl N-(6-methyl-2-pyridyl)aminomethylenemalonamates (263, = Me, R1 = Et and isoamyl) was isolated in 90% yield (87SC549). 

N-Ethyl-yV-(6-methyl-2-pyridyl)aminomethylenemalonate (265, R = Me, R1 = R2 = Et) was prepared in 16-66% yields in the reaction of 2-(ethylamino)-6-methylpyridine, diethyl malonate, and ethyl orthoformate in the presence of acidic catalysts (AcOH, EtCOOH, Dianion WK-11) at 150-160°C for 2-3.5 hr [74JAP(K) 109383],... 

The monoethyl A -(6-methyl-2-pyridyl)aminomethylenemalonate was prepared in 34% yield in the reaction of monoethyl malonate, ethyl orthoformate, and 2-amino-6-methylpyridine in the presence of catalytic amounts of A1C13 at 110-115°C for 45 min (72AF815). 

V-(6-Methyl-2-pyridyl)aminomethylenemalonate (306) was obtained in 86% yield in the reaction of a l l mixture of N-(6-methyl-2-pyridyl)-formimidate (305) and diethyl malonate at 150°C for l hr [74JAP(K)93370]. 

Shur and Israelstam carried out the cyclization of 2-pyridylaminomethy-lenemalonates (1001) in polyphosphoric acid at 110°C for 4 hr (68JOC3015). They reported that pyrido[ 1,2-a]pyrimidine-3-carboxylates (1002) were obtained, even if they started from A/-(6-methyl- or 4,6-dimethyl-2-pyri-dyl)aminomethylenemalonates (1001, R = Me, R1 = H, 4-Me). However, it was later demonstrated that, in the case of the 6-methyl derivative (1001, R = Me, R1 = H), instead of the pyrido[ 1,2-a]pyrimidine-3-carboxylate (1002, R = Me, R1 = H), the ethyl, hydrogen Al-(6-methyl-2-pyridyl)ami-nomethylenemalonate (378, R = Me) was probably obtained. The latter... 

Pyrido[l,2-a]pyrimidine-3-carboxylate (1010, R = Me) was prepared in 90% yield on the cyclization of diethyl A-(3-cyano-4-methyl-2-pyridyl)ami-nomethylenemalonates by heating in Dowtherm A at 255°C for 1.5 hr (84KGS799). 

V-(6-Methyl-2-pyridyl)aminomethylenemalonate (1001, R = Me, R1 = H) was cyclized to 1,8-naphthyridine (1003, R = Me, R1 = H) in 70% yield in a continuous-operation wiped-film reactor with control of the residence time, whereas in a conventional wiped-film reactor, the yield was 25-30% (79MI2). On heating in dodecylbenzene or in diethyl phthalate at 285-300°C for 3-6 min, the yield was 90% (73MIP3). 

The ring closure of diethyl /V-(6-methyl-2-pyridyl)aminomethylenemalo-nate(1001, R = Me,R = H) was carried out on a large scale in chlorobenzene on the action of a mixture of phosphoryl chloride and polyphosphoric acid at 125-130°C for 10-12 hr to give the hydrochloride of pyrido[l,2-a]pyrimidine-3-carboxylate (1002, R = Me, R1 = H) in good yield after treatment of the reaction mixture with ethanol (77MIP1). 

AK5-Hydroxy-6-methyl-2-pyridyl)aminomethylenemalonate (1492, R = H) was alkylated with alkyl halides in DMF in the presence of potassium carbonate at 90-110°C for 1 hr to give the 5-alkoxy derivatives (1492, R = Et, /Pr, CH2Ph, CH2OMe) [81JAP(K)131583]. 

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