171111-15-2

Upstream product

• 38622-91-2 [(p-methylphenyl)sulfonylmethyl]isonitrile 
• 89896-01-5 3-nitropentan-2-ol acetate 
• 184422-60-4 3-Ethyl-4-methyl-5-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylic acid ethyl ester 
• 184422-66-0 3-Ethyl-4-methyl-5-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylic acid 
• 98-59-9 p-toluenesulfonyl chloride 
• 76367-42-5 ethyl 5-carboxy-3-ethyl-5-iodo-4-methylpyrrole-2-carboxylate 
• 4949-58-0 2-(ethyloxycarbonyl)-3-ethyl-4-methylpyrrole 
• 184422-74-0 3-Ethyl-2-iodo-4-methyl-5-(toluene-4-sulfonyl)-1H-pyrrole 
• 152796-95-7 3-ethyl-4-methyl-2-(p-toluenesulfonyl)-1H-pyrrole 

Downstream Products

• 226223-25-2 2-bromo-3-ethyl-4-methyl-5-p-toluenesulfonyl-pyrrole 
• 1224956-51-7 C₁₆H₁₉NO₄S 
• 1224956-46-0 C₁₄H₁₅NO₃S 
• 184422-85-3 3-ethyl-4-methyl-5-p-toluenesulfonyl-3-pyrrolin-2-one 
• 766-36-9 3-ethyl-4-methyl-3-pyrrolin-2-one 

Relevant academic research and scientific papers

An improved coupling procedure for the Barton-Zard pyrrole synthesis

An improved final step in the Barton-Zard pyrrole synthesis uses inexpensive potassium carbonate as base in the coupling-cyclization reaction of vic-nitro-acetates with isocyanides. In this modification the isolated yields of synthetically useful 2-carboalkoxypyrroles (1a,b and 3) and 2-(p-toluenesulfonyl)pyrroles (2a,b) consistently rise to the 78-89% range. Conversion of 2a to 5-(p-toluenesulfonyl)-2-pyrrolinone 4 is conveniently and directly achieved by reaction with 30% hydrogen peroxide in acetic acid, thus circumventing the commonly used two step procedure involving bromination followed by solvolysis.

An intramolecularly hydrogen bonded dihydrotripyrrinone

A yellow tripyrrole analog (1) of bilirubin has been synthesized, and its lone propionic acid group is found to engage in conformation determining, intramolecular hydrogen bonding in solution and in the crystal. Molecular modelling and X-ray crystallography reveal an abbreviated ridge-tile or L-shape conformation in which an essentially planar dipyrrinone is hydrogen bonded to the single opposing propionic acid group. In the (arbitrary) (P)-helicity ridge-tile, the torsion angles about C(10) are computed to be 55° and 61° by molecular dynamics and found to be 66° and 53° in the crystal. Such torsion angles lead to an interplanar dihedral angle (～93°) between the dipyrrinone and its adjoining pyrrole that is very close to the dihedral angle (～98°) found in intramolecularly hydrogen bonded bilirubin.

Syntheses of 3,4-disubstituted 2-tosylpyrroles and 5-tosyl-1,5-dihydro-2H-pyrrol-2-ones starting from ethyl 3,4-disubstituted 2-pyrrolecarboxylates

The syntheses of 3,4-disubstituted 2-tosylpyrroles and 5-tosyl-1,5-dihydro-2H-pyrrol-2-ones were accomplished via 3,4-disubstituted 2-iodo-5-tosylpyrroles starting from ethyl 3,4-disubstituted 2-pyrrolecarboxylates.

Rearrangement of tosyl group of 3,4-disubstituted 2-tosylpyrroles under mild acidic conditions

Tosyl group of 3,4-disubstituted 2-tosylpyrroles easily rearranged from 2- to 5- position by treatment with TFA.The ratio of the regioisomers at equilibrium was definitely influenced by the bulkiness of the substituent at 3-position of starting 2-tosylpyrroles.