90329-58-1

Upstream product

• 103-79-7 1-phenyl-acetone 
• 74305-27-4 ((CH₃(CH₂)3)3P)Co(HONC(CH₃)C(CH₃)NO)2(N₄C(CH₃)) 
• 100-39-0 benzyl bromide 
• 4076-36-2 5-methyl-1,2,3,4-tetrazole 

Downstream Products

• 142868-25-5 C₁₇H₁₇N₄O⁽¹⁺⁾*F₆P^(1-) 
• 142868-41-5 3-Benzyl-3a-methyl-5-phenyl-3a,6-dihydro-3H-imidazo[1,2-d]tetrazole 

Relevant academic research and scientific papers

Derisking the Cu-Mediated 18F-Fluorination of Heterocyclic Positron Emission Tomography Radioligands

Molecules labeled with fluorine-18 (18F) are used in positron emission tomography to visualize, characterize and measure biological processes in the body. Despite recent advances in the incorporation of 18F onto arenes, the development of general and efficient approaches to label radioligands necessary for drug discovery programs remains a significant task. This full account describes a derisking approach toward the radiosynthesis of heterocyclic positron emission tomography (PET) radioligands using the copper-mediated 18F-fluorination of aryl boron reagents with 18F-fluoride as a model reaction. This approach is based on a study examining how the presence of heterocycles commonly used in drug development affects the efficiency of 18F-fluorination for a representative aryl boron reagent, and on the labeling of more than 50 (hetero)aryl boronic esters. This set of data allows for the application of this derisking strategy to the successful radiosynthesis of seven structurally complex pharmaceutically relevant heterocycle-containing molecules.

ADDITION REACTION OF TRIMETHYLSILYL AZIDE TOWARDS KETONES AND FACILE FORMATION OF TETRAZOLE DERIVATIVES

In the presence of Lewis acid such as SnCl2, the reactions of trimethylsilyl azide with ketones readily gave 1:1- or 1:2-adduct, which reacted with Lewis acid to afford tetrazole.

Regiospecific Coordination of Ambidentate Tetrazoles to Cobalt Oximes

A series of complexes of the type (n-Bu3P)Co(DH)2(5R-tetrazolate) (DH is the monoanion of dimethylglyoxime; R = CF3, CH3, C6H5, C6H5CH2, (CH3)2N, 4-FC6H4, and 3-FC6H4) have been prepared and characterized by conductance studies, elemental analyses, and 1H, 13C, 31P, and 19F NMR spectroscopy.Quantum-mechanical calculations (MINDO/3) indicate that the N1 nitrogens of the aromatic tetrazolate anion are slightly more nucleophilic than the N2, yet in each complex the ambidentate tetrazolate anion is coordinated to cobalt via the N2 nitrogen, showing that regiospecific coordination is sterically induced.This is in marked contrast to tetrazole complexes of platinum and palladium wherein both N1 and N2 bound tetrazoles are found in approximately equal abundances.These cobalt complexes react with alkyl halides such as CH3I and C6H5CH2Br to produce exclusively 1,5-disubstituted tetrazoles.None of the isomeric 2,5-disubstituted tetrazole is detected in these reactions in marked contrast to the reactions of sodium tetrazolates or gold, palladium, or platinum tetrazolate complexes with alkyl halides which produce mixtures of the 1,5- and 2,5-disubstituted tetrazoles.The crystal structure of n-Bu3PCo(DH)2(5-CF3-tetrazolate) was determined using three-dimensional X-ray diffraction techniques.The molecule crystallizes in the orthorhombic space group Pbca in a unit cell of dimensions a = 12.040(2) Angstroem, b = 21.531(3) Angstroem, c = 23.536(4) Angstroem, ρcalcd = 1.368 g/cm3, ρobsd = 1.374 g/cm3.Refinement converged to 5.4percent with 2525 independent reflections.The tetrazolato ring is coordinated to cobalt via N2 and is planar.The Co-P bond (2.263 Angstroem) is one of the shortest observed in LCo(DH)2X structures.The acute dihedral angle between the planes of the two glyoximato groups (10.4 deg) is among the largest dihedral angles observed in structures of this type.Surprisingly, the tetrazolato ring does not lie in the fold of the two glyoximato rings but is nearly normal to it.Thus, the regiospecificity of the alkylations of the coordinated tetrazolate with alkyl halides is sterically promoted.