38195-81-2

Upstream product

• 186581-53-3 diazomethane 
• 824-40-8 2-pyridinecarboxylic acid N-oxide 
• 67-56-1 methanol 
• 2459-07-6 methyl pyridine-2-carboxylate 
• 2524-52-9 ethyl-2-picolinate 
• 98-98-6 2-Picolinic acid 
• 18107-18-1 diazomethyl-trimethyl-silane 

Downstream Products

• 2459-07-6 methyl pyridine-2-carboxylate 
• 6974-72-7 2-pyridinecarboxamide 1-oxide 
• 54633-17-9 2-(hydrazinecarbonyl)pyridine-1-oxide 
• 30062-34-1 methyl 6-oxo-1,6-dihydropyridine-2-carboxylate 
• 6636-55-1 methyl 6-chloropicolinate 
• 24484-93-3 4-Chloro-pyridine-2-carboxylic acid methyl ester 
• 32559-18-5 methyl piperidine-2-carboxylate hydrochloride 
• 36052-26-3 methyl 6-aminopyridine-2-carboxylate 

Relevant academic research and scientific papers

Visible-Light-Induced ortho-Selective Migration on Pyridyl Ring: Trifluoromethylative Pyridylation of Unactivated Alkenes

The photocatalyzed ortho-selective migration on a pyridyl ring has been achieved for the site-selective trifluoromethylative pyridylation of unactivated alkenes. The overall process is initiated by the selective addition of a CF3 radical to the alkene to provide a nucleophilic alkyl radical intermediate, which enables an intramolecular endo addition exclusively to the ortho-position of the pyridinium salt. Both secondary and tertiary alkyl radicals are well-suited for addition to the C2-position of pyridinium salts to ultimately provide synthetically valuable C2-fluoroalkyl functionalized pyridines. Moreover, the method was successfully applied to the reaction with P-centered radicals. The utility of this transformation was further demonstrated by the late-stage functionalization of complex bioactive molecules.

Hydroheteroarylation of Unactivated Alkenes Using N-Methoxyheteroarenium Salts

We report the first reductive coupling of unactivated alkenes with N-methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts under hydrogen atom transfer (HAT) conditions, and an expanded scope for the coupling of alkenes with N-methoxy pyridinium salts. N-Methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts are accessible in 1-2 steps from the commercial arenes or arene N-oxides (25-99%). N-Methoxy imidazolium salts are accessible in three steps from commercial amines (50-85%). In total 36 discrete methoxyheteroarenium salts bearing electron-donating, electron-withdrawing, alkyl, aryl, halogen, and haloalkyl substituents were prepared (several in multigram quantities) and coupled with 38 different alkenes. The transformations proceed under neutral conditions at ambient temperature, provide monoalkylation products exclusively, and form a single alkene addition regioisomer. Preparatively useful and complementary site selectivities in the addition of secondary and tertiary radicals to pyidinium salts are documented: harder secondary radicals favor C-2 addition (2->10:1), while softer tertiary radicals favor bond formation to C-4 (4.7->29:1). A diene possessing a 1,2-disubstituted and 2,2-disubstituted alkene undergoes hydropyridylation at the latter exclusively (61%) suggesting useful site selectivities can be obtained in polyene substrates. The methoxypyridinium salts can also be employed in dehydrogenative arylation, borono-Minisci, and tandem arylation processes. Mechanistic studies support the involvement of a radical process.

One drop chemical derivatization - DESI-MS analysis for metabolite structure identification

Structural elucidation of metabolites is an important part during the discovery and development process of new pharmaceutical drugs. Liquid Chromatography (LC) in combination with Mass Spectrometry (MS) is usually the technique of choice for structural identification but cannot always provide precise structural identification of the studied metabolite (e.g. site of hydroxylation and site of glucuronidation). In order to identify those metabolites, different approaches are used combined with MS data including nuclear magnetic resonance, hydrogen/deuterium exchange and chemical derivatization followed by LC-MS. Those techniques are often time-consuming and/or require extra sample pre-treatment. In this paper, a fast and easy to set up tool using desorption electrospray ionization-MS for metabolite identification is presented. In the developed method, analytes in solution are simply dried on a glass plate with printed Teflon spots and then a single drop of derivatization mixture is added. Once the spot is dried, the derivatized compound is analyzed. Six classic chemical derivatizations were adjusted to work as a one drop reaction and applied on a list of compounds with relevant functional groups. Subsequently, two successive reactions on a single spot of amoxicillin were tested and the methodology described was successfully applied on an in vitro incubated alprazolam metabolite. All reactions and analyses were performed within an hour and gave useful structural information by derivatizing functional groups, making the method a time-saving and efficient tool for metabolite identification if used in addition or in some cases as an alternative to common methods.

Ligands for copper-catalyzed C-N bond forming reactions with 1 Mol% CuBr as catalyst

Several new ligands were designed to promote copper-catalyzed Ullman C-N coupling reactions. In this group, 8-hydroxyquinolin-N-oxide was found to serve as a superior ligand for CuBr-catalyzed coupling reactions of aryl iodides, bromides, and chlorides with aliphatic amines and N-heterocycles under a low catalyst loading (1% [Cu] mol). Reactions with the inexpensive catalytic system display a high functional group tolerance as well as excellent chemoselectivity.

A general and efficient 2-amination of pyridines and quinolines

(Chemical Equation Presented) Pyridine N-oxides were converted to 2-aminopyridines in a one-pot fashion using Ts2O-t-BuNH2 followed by in situ deprotection with TFA. The amination proceeded in high yields, excellent 2-/4-selectivity, and with good functional group compatibility. 2-Amino (iso)quinolines were also obtained in the same manner. Combined with the simple oxidation of pyridines to pyridine N-oxides, this method provides a general and efficient way for amination of 2-unsubstituted pyridines.

A simple and efficient method for the preparation of pyridine-N-oxides II

Oxidation of pyridines with bis(trimethylsilyl)peroxide in the presence of catalytic amounts of inorganic rhenium derivatives gives high yields of their analytically pure N-oxides by simple work-ups, typically a filtration or a Kugelrohr distillation.

Synthesis of a tritium labelled analog of the novel hematoregulatory agent SB 209978

[3H]-SB 209978 (10) was synthesized in 6 steps from phenylene diamine dihydrochloride. A key aspect was the regioselective synthesis of 6-chloropicolinic acid (7). This was condensed with diamine 6 and the resulting product was deprotected to give 9. Palladium catalyzed 3H-hydrogenolysis of the chloropyridine rings gave the final produce 10.