Welcome to LookChem.com Sign In|Join Free

CAS

  • or

189503-05-7

Post Buying Request

189503-05-7 Suppliers

Recommended suppliersmore

  • Product
  • FOB Price
  • Min.Order
  • Supply Ability
  • Supplier
  • Contact Supplier

189503-05-7 Usage

Check Digit Verification of cas no

The CAS Registry Mumber 189503-05-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,8,9,5,0 and 3 respectively; the second part has 2 digits, 0 and 5 respectively.
Calculate Digit Verification of CAS Registry Number 189503-05:
(8*1)+(7*8)+(6*9)+(5*5)+(4*0)+(3*3)+(2*0)+(1*5)=157
157 % 10 = 7
So 189503-05-7 is a valid CAS Registry Number.

189503-05-7Upstream product

189503-05-7Relevant articles and documents

The fluoride anion-catalyzed sulfurization of thioketones with elemental sulfur leading to sulfur-rich heterocycles: First sulfurization of thiochalcones ?

Bielinski, Dariusz M.,Heimgartner, Heinz,Mloston, Grzegorz,Urbaniak, Katarzyna,Wreczycki, Jakub

, (2021/06/12)

Fluoride anion was demonstrated as a superior activator of elemental sulfur (S8) to perform sulfurization of thioketones leading to diverse sulfur-rich heterocycles. Due to solubility problems, reactions must be carried out either in THF using tetrabutylammonium fluoride (TBAF) or in DMF using cesium fluoride (CsF), respectively. The reactive sulfurizing reagents are in situ generated, nucleophilic fluoropolysulfide anions FS(8?x)?, which react with the C=S bond according to the carbophilic addition mode. Dithiiranes formed thereby, existing in an equilibrium with the ring-opened form (diradicals/zwitterions) are key-intermediates, which undergo either a step-wise dimerization to afford 1,2,4,5-tetrathianes or an intramolecular insertion, leading in the case of thioxo derivatives of 2,2,4,4-tetramethylcyclobutane-1,3-dione to ring enlarged products. In reactions catalyzed by TBAF, water bounded to fluoride anion via H-bridges and forming thereby its stable hydrates is involved in secondary reactions leading, e.g., in the case of 2,2,4,4-tetramethyl-3-thioxocyclobutanone to the formation of some unexpected products such as the ring enlarged dithiolactone and ring-opened dithiocarboxylate. In contrast to thioketones, the fluoride anion catalyzed sulfurization of their α,β-unsaturated analogues, i.e., thiochalcones is slow and inefficient. However, an alternative protocol with triphenylphosphine (PPh3) applied as a catalyst, offers an attractive approach to the synthesis of 3H-1,2-dithioles via 1,5-dipolar electrocyclization of the in situ-generated α,β-unsaturated thiocabonyl S-sulfides. All reactions occur under mild conditions and can be considered as attractive methods for the preparation of sulfur rich heterocycles with diverse ring-size.

FROM THIIRANES TO THIOCARBONYL S-SULFIDES; RECENT RESULTS

Huisgen, Rolf

, p. 63 - 94 (2007/10/02)

A novel nucleophilic catalysis for the desulfurization of thiiranes is described.Triphenylthiirane is quantitatively converted to triphenylethylene by some molpercent sodium thiophenoxide or other thiolates in DMSO at 35 deg C.A rapid initial reaction is retarded by the eliminated sulfur leading to a pseudo-first-order reaction under quasi-stationary conditions.The suggested mechanism is based on structure-rate relationships. - The thiolate-catalyzed reaction of cis-2,3-diphenylthiirane is exceptional in furnishing equimolar quantities of cis-stilbene and 3,4,6,7-tetraphenyl-1,2,5-trithiepane (2 diastereoisomers with bilateral symmetry); mechanistic implications - thiolate attack on sulfur or C-atom of thiirane - are discussed. - Desulfurization of 2,2-diphenylthiirane by thiobenzophenone or other thioketones gives access to thiocarbonyl S-sulfides ("thiosulfines") which are intercepted by 1,3-cycloadditions to activated acetylenes or to thiones.

Post a RFQ

Enter 15 to 2000 letters.Word count: 0 letters

Attach files(File Format: Jpeg, Jpg, Gif, Png, PDF, PPT, Zip, Rar,Word or Excel Maximum File Size: 3MB)

1

What can I do for you?
Get Best Price

Get Best Price for 189503-05-7