19978-33-7

Basic information

• Product Name: 5-BROMO-2H-PYRAN-2-ONE,95%
• Synonyms: 5-BROMO-2H-PYRAN-2-ONE,95%;5-Bromo-2H-pyran-2-one;5-Bromo-2-pyrone;5-Bromo-α-pyrone;2H-Pyran-2-one, 5-broMo-
• CAS NO: 19978-33-7
• Molecular Formula: C₅H₃BrO₂
• Molecular Weight: 174.98
• Mol File: 19978-33-7.mol
• Article Data: 13

Chemical Properties

• Melting Point: 61-63 °C
• Boiling Point: 233.7±33.0 °C(Predicted)
• Appearance: /
• Density: 1.882±0.06 g/cm3(Predicted)
• CAS DataBase Reference: 5-BROMO-2H-PYRAN-2-ONE,95%(CAS DataBase Reference)
• NIST Chemistry Reference: 5-BROMO-2H-PYRAN-2-ONE,95%(19978-33-7)
• EPA Substance Registry System: 5-BROMO-2H-PYRAN-2-ONE,95%(19978-33-7)

Safety Data

• Hazardous Substances Data: 19978-33-7(Hazardous Substances Data)

Usage

Synthesis Reference(s)

The Journal of Organic Chemistry, 34, p. 2239, 1969 DOI: 10.1021/jo01260a001Tetrahedron Letters, 33, p. 7839, 1992 DOI: 10.1016/S0040-4039(00)74757-5

Upstream product

• 3393-45-1 5,6-dihydro-pyran-2-one 
• 500-05-0 2H-pyran-2-one-5-carboxylic acid 
• 137776-72-8 3,5-dibromo-5,6-dihydro-2H-pyran-2-one 
• 104184-64-7 3-Bromo-5,6-dihydro-2H-pyran-2-one 
• 283156-10-5 3-bromo-6-methoxy-3,6-dihydro-2H-pyran 
• 283156-05-8 methyl 2,3-dideoxy-α,β-DL-glycero-pent-2-enopyranoside 
• 35436-57-8 6-hydroxy-3,6-dihydro-2H-pyran-3-one 
• 60249-17-4 6-methoxy-2H-pyran-3(6H)-one 
• 53646-72-3 5-bromo-5,6-dihydro-2H-pyran-2-one 
• 504-31-4 pyran-2-one 
• 22682-17-3 5,6-dibromo-5,6-dihydro-2H-pyran-2-one 

Downstream Products

• 291506-54-2 5-(4-fluoro-phenyl)-pyran-2-one 
• 291506-55-3 5-(4-methoxy-phenyl)-pyran-2-one 
• 291506-57-5 5-(4-methylsulfanyl-phenyl)-pyran-2-one 
• 465-20-3 bufalin 

Relevant articles and documents

Selective inhibition of the cellular sodium pump by emicymarin and 14? anhydroxy bufadienolides

Partial inhibition of the sodium pump (Na/K-ATP-ase) by a circulating inhibitor is known to occur in humans. The objectives of this study were to determine the effects of novel bufadienolides lacking an oxygen at C14 on sodium pumps in human erythrocytes and leucocytes, dog kidney and pig brain and to document the importance of the stereochemistry at C17 on the ability to inhibit these sodium pumps. 14α bufadienolides were weak inhibitors of all preparations studied. 3?-OH,5?,14? bufadienolide produced near-total inhibition of dog kidney and pig brain Na/K-ATP-ase. Over the same concentration range, it maximally inhibited the sodium pump of erythrocytes by 70% and leucocytes by 47%. The inhibition profile induced in the leucocyte sodium pump deviated significantly from the simple sigmoidal relationship present in the other preparations over the 3 × 10-5 to 1 × 10-7 mol/l concentration range. Allo-emicymarin (17α) was confirmed to be a weak inhibitor of the sodium pump/ATP-ase compared with emicymarin (17?) but both were weaker inhibitors of the leucocyte sodium pump than that of the other preparations. Molecules with the C14 in the ? configuration are more efficacious than in the α configuration. In the case of emicymarin, the attachment of the furone at C17 in the α configuration results in substantially weaker inhibitory activity than in the beta configuration, seen in most cardenolides and bufadienolides. Unlike ouabain and bufalin that show no specificity of action in these preparations, 3?- OH,5?,14? bufadienolide selectively inhibits the activity of at least one low-prevalence subset of the leucocyte Na/K-ATP-ase.

A Suzuki coupling approach to bufadienolides

A high yielding route to bufadienolide type steroids using a novel Suzuki coupling reaction between a range of steroid vinyl triflates and 2-pyrone-5-boronate 11 is presented.

3-Bromo-2-Pyrone: An Alternative and Convenient Route to Functionalized Phosphinines

The facile access to 3-bromo-2-pyrone allows the preparation of 6-bromo-2-trimethylsilyl-phosphinine by a [4+2] cycloaddition with Me3Si-C≡P for the first time. The regioselectivity of this reaction could be verified by means of single crystal X-ray diffraction of the corresponding W0complex. In the presence of ZnBr2and dppp (1,3-bis(diphenylphosphino)propane) as a bidentate ligand, the bromo-phosphinine quantitatively undergoes a Negishi cross-coupling reaction with PhLi that selectively leads to 6-phenyl-2-trimethylsilyl-phosphinine. This heterocycle could again be characterized by means of X-ray diffraction as a W0complex. These results describe a new and convenient route to 2,6-disubstituted phosphinines that makes use of readily available starting materials.

Modified Nucleosides for Rna Interference

The present invention relates to the use of modified nucleotides and single or double stranded oligonucleotides having at least one of said modified nucleotides for performing RNA interference. The modified nucleotides are selected from 6-membered ring containing nucleotides such as hexitol, altritol, O-substituted or O-alkylated altritol, cyclohexenyl, ribo-cyclohexenyl and O-substituted or O-alkylated ribo-cyclohexenyl nucleotides. The present invention also relates to novel modified nucleosides or nucleotides and to the use of the novel modified nucleosides and nucleotides in single or double stranded oligonucleotides for RNA interference, antisense therapy or other applications.