2.4- dimethylpyrrole, oxidation

Phosphoryl chloride Carbon disulflde, A,A-dimethylformamide, 2,5-dimethylpyrrole, 2,6-dimethyl-pyridine 1-oxide, dimethylsulfoxide, water, zinc... 

Petrillo reported that the bis-acetoxymethylpyrrole 83 undergoes a sequential Diels-Alder reaction of the in situ generated 2,3-dimethylpyrrole with carbodienophiles (such as maleic anhydride, maleimide, ethyl maleate, fumaronitrile, and ethyl acrylate) to afford the octahydrocarbazoles 84 which can be oxidized with DDQ to the corresponding carbazole derivatives . 

The chemical structure of 2,5-hexanedione suggested that it could react with lysine side-chain amino groups in proteins to form pyrroles (see Figure 2-7). In vitro experiments showed that this was, in fact, the case, and that the modified proteins can undergo secondary reactions to yield oxidized and polymeric products (DeCaprio et al. 1982 Graham et al. 1982). Oral administration of 2,5-hexanedione produced evidence that this process can take place in vivo as demonstrated by the detection of 2,5-dimethylpyrrole adducts in serum and axonal cytoskeletal proteins (DeCaprio and O Neill 1985). When a series of... 

By means of oxidation of the initially formed 3,4-disubstituted 5-bromo-2-bromomethylpyrrole, bromine converted 3,4-disubstituted-2-methylpyr-roles and their 5-carboxylic acids into 5-bromo-5 -bromomethyl-2,2 -dipyrrolylmethanes. Similar reaction with sulfuryl chloride led to the analogous chloro species (77MI2). Whereas treatment of 2-aroyl-l,3-dimethylpyrrole-5-acetic esters with NBS brominated the vacant ring carbon, the related oxalate ester gave the 3-bromomethyl derivative (80JMC98). 

Dimethylpyrrole is very readily oxidized in the air to a red resinous substance. If it is not used immediately, it should be stored under nitrogen or sealed in a glass vial under a vacuum. 

A mixture of DL-threonine and DL-allothreonine was prepared by the hydrogenation of ethyl diazoacetoacetate over paltinum oxide in 70% ethanol containing sulfuric acid (eq. 9.90). 2,4-Dimethylpyrrole-3,5-dicarboxylic acid diethyl ester was also obtained as a byproduct. 

Attempts to oxidize 2,5-dimethylpyrrole were carried out by Angeli38 and Pieroni,51 but without significant results. It seems that at least one a position must be free, while /S positions are only slightly reactive toward oxidation. 

Dimethylpyrrole was oxidized in organic solvents at room temperature 50 a A 4-pyrrolin-2-one (52) was isolated, along with quantities of polymeric oily products. 

By oxidation in acetic acid of 2,4-dimethylpyrrole, a compound Ci2H20N2O5 (still unelucidated structure), which by hydrolysis gives CH3COCH2CH(CH3)COOH, was obtained by Pieroni and Veremeenco.51... 

SAFETY PROFILE Poison by inhalation and ingestion. A corrosive eye, skin, and mucous membrane irritant. Potentially explosive reaction with water evolves hydrogen chloride and phosphine, which then ignites. Explosive reaction with 2,6-dimethylpyridine N-oxide, dimethyl sulfoxide, ferrocene-1,1 -dicarboxylic acid, pyridine N-oxide (above 60°C), sodium -L heat. Violent reaction or ignition with BI3, carbon disulfide, 2,5-dimethyl pyrrole + dimethyl formamide, organic matter, zinc powder. Reacts with water or steam to produce heat and toxic and corrosive fumes. Incompatible with carbon disulfide, N,N-dimethyl-formamide, 2,5-dimethylpyrrole, 2,6-dimethylpyridine N-oxide, dimethylsulfoxide, ferrocene-1,1-dicarboxylic acid, water, zinc. When heated to decomposition it emits highly toxic fumes of Cl" and POx. 

OXICLORURO de FOSFORO (10025-87-3) Fumes in moist air. Contact with water, steam, or alcohols produces hydrochloric acid, phosphoric acid, and phosphine gas, which is pyrophoric, with possible ignition or explosion (may be a delayed reaction). Contact with air produces corrosive fumes. Violent reaction with carbon disulfide, 2,6-dimethylpyiidine-M-oxide, dimethyl sulfoxide, ferrocene-l,l -dicarboxylie acid, pyridine, zinc powder. Reacts, possibly -violently, with acids, alkali metals, alkalis, combustible materials, dimethyl formamide, organic matter, zinc powder. Incompatible with acetic anhydride, iV,A -dimethyl formamide, 2,5-dimethylpyrrole, sodium. Rapid corrosion of steel and most metals, except lead, occurs in the presence of moisture. 

---