88692-03-9

Basic information

• Product Name: 3,3,4,4(2H,5H)-Thiophenetetracarboxylic acid, 2,2-diphenyl-, tetramethyl ester
• CAS NO: 88692-03-9
• Molecular Formula: C24H24O8S
• Molecular Weight: 472.516
• Mol File: 88692-03-9.mol
• Article Data: 3

Chemical Properties

• CAS DataBase Reference: 3,3,4,4(2H,5H)-Thiophenetetracarboxylic acid, 2,2-diphenyl-, tetramethyl ester(CAS DataBase Reference)
• NIST Chemistry Reference: 3,3,4,4(2H,5H)-Thiophenetetracarboxylic acid, 2,2-diphenyl-, tetramethyl ester(88692-03-9)
• EPA Substance Registry System: 3,3,4,4(2H,5H)-Thiophenetetracarboxylic acid, 2,2-diphenyl-, tetramethyl ester(88692-03-9)

Safety Data

• Hazardous Substances Data: 88692-03-9(Hazardous Substances Data)

Upstream product

• 107-13-1 acrylonitrile 
• 908093-98-1 diazodiphenylmethane 
• 1733-15-9 Tetramethyl ethylenetetracarboxylate 
• 79999-60-3 2,5-dihydro-2,2-diphenyl-1,3,4-thiadiazole 
• 79999-62-5 thiobenzophenone S-methylide 

Relevant articles and documents

'Thiobenzophenone S-Methylide" (=(Diphenylmethylidenesulfonio)methanide), and C,C Multiple Bonds: Cycloadditions and Dipolarophilic Reactivities

Thiobenzophenone and diazomethane afford thiadiazoline 1 at -78 deg C. By elimination of N2 from 1 at -45 deg C (t1/2 ca. 1 h), (diphenylmethylidenesulfonio)methanide (2), which cannot be isolated but is interceptible by dipolarophiles, is set free. The nucleophilic 1,3-dipole 2 undergoes cycloadditions with electrophilic C,C multiple bonds; the structures of 16 cycloadducts were elucidated. One-step and two-step cycloaddition pathways are discussed in the light of the steric course observed for (E)/(Z)-isomeric ethylene derivatives. Competition experimetns with pairs of dipolarophiles at -45 deg C and HPLC analysis of the adducts provided relative rate constants of 26 dipolarophiles, involving 2 CC, 13 C=C, 9 C=S, and 2 N=N bonds. In accordance with Sustmann's reactivity model of concerted cycloadditions, 2 shows the highest selectivity of all known 1,3-dipoles, i. e., the largest spread of rate constants (krel = 1 for methyl propiolate and 33 x 106 for TCNE). As a consequence of low LU energies, thiones are very active dipolarophiles, and fluorene-9-thione (krel = 79 x 106) stands at the top.

NEW REACTIONS OF THIOBENZOPHENONE S-METHYLIDE

2,2-Diphenyl-1,3,4-thiadiazoline, prepared from thiobenzophenone and diazomethane at -78 deg C, extrudes N2 at -45 deg C and allows to study in situ 1,3-cycloadditions of thiobenzophenone S-methylide (3) with electrophilic C=S, C=C, CC, and N=N bonds.