Pyrrole methyl

Oxidation of the 3-(hydroxyalkyl)pyrrole derivative gives a pure 3-acylpyrrole derivative which is difficult to obtain by direct substitution in the pyrrole ring. Acylation of pyrrole yields 1- and/or 2-acetyl pyrrole, whereas acylation of 1-methyl pyrrole forms both 2- and 3-acetyl-1-methyl-... 

Methyl pyrrole Pyrrole, 1-methyl- (8) 1 H-Pyrrole, 1-methyl- (9) 96-54-8... 

Photochemical [2 + 2] cycloaddition is a powerful way to produce cyclobutanes, which, in turn, are reactive synthesis intermediates. N-Methylpyrrole adds aldehydes via [2 -I- 2] photocycloaddition to give transient oxetanes with high regioselectivity Ring-opening produces 3-(oi-hydroxyalkyl)pyrroles which are oxidized easily to 3-arylpyrroles, such as 3-BUTYROYL-l-METHYL-PYRROLE. With a special apparatus, ethylene is conveniently added to 3-methyl-... 

Apart from the A-methyl group, three double-bond equivalents and three multiplets remain in the chemical shift range appropriate for electron rich heteroaromatics, Sh = 6.2 to 6.9. A-Methyl-pyrrole is such a compound. Since in the multiplets at Sh = 6.25 and 6.80 the Jhh coupling of 4.0 Hz is appropriate for pyrrole protons in the 3- and 4-positions, the pyrrole ring is deduced to be substituted in the 2-position. 

Methyl pyrrole-l-carboxylate (14) and hot dimethyl acetylenedi-carboxylate give trimethyl pyrrole-1,3,4-tricarboxyIate (15) and acetylene, presumably through the addition-elimination sequence shown. Dimethyl acetylenedicarboxylate and 1-methylpyrrole com-... 

Diels et al. showed that acetylenedicarboxylic acid and 1-methyl-pyrrole gave l-methyl-2-pyrrylmaleic anhydride (41) and a second compound. The anhydride on hydrogenation and conversion to the corresponding dimethyl ester gave the same product as obtained from 1-methylpyrrole and maleic anhydride, followed by hydrolysis and... 

Methyl pyrrole-l-carboxylate and dimethyl acetylenedicarboxylate combine at 170°-200°C, giving trimethyl pyrrole-1,3,4-tricarboxylate (46) and acetylene. This reaction probably proceeds through the... 

The first question one asks is why does the reaction with 2-methyl-pyrrole stop at the dimer stage, whereas the pyrrole dimer itself cannot be isolated, but reacts further to form the trimer. The answer probably lies in the greater electrophilic reactivity of... 

As is the case for 2 + 2 strategies for porphyrin syntheses, the 3 + 1 approach can also be carried out at a lower oxidation level using 2,5-bis[(dimethylamino)methyl]pyrroles 4 instead of pyrroledicarbaldehydes.50... 

In certain cases where the heteroaromatic amine is insufficiently soluble in aqueous acid, it can be dissolved in the minimum volume of an organic solvent miscible with water. Dilute mineral acid and a solution of sodium nitrite are then added. An example is the diazotization of 2-phenyl-3-amino-4-acetyl-5-methyl-pyrrole (Dattolo et al., 1983). 

In recent years further concepts have been developed for the construction of polymer-based diodes, requiring either two conjugated polymers (PA and poly(A-methyl-pyrrole) 2 > or poly(A-methylpyrrole in a p-type silicon wafer solid-state field-effect transistor By modifying the transistor switching, these electronic devices can also be employed as pH-sensitive chemical sensors or as hydrogen or oxygen sensors 221) in aqueous solutions. Recently a PPy alcohol sensor has also been reported 222). 

Selective oxidation of methyl pyrroles 65 possessing an a-carboxylic ester and sensitive p-substituents can be accomplished using cerium triflate in methanol <96TL315>. Moreover, the resultant a-methoxymethylpyrroles 66 may be converted to dipyrrylmethanes 67 in a "one-pot" sequence by treatment with 48% HBr. The dipyrrylmethanes, in turn, can be further oxidized to dipyrryl ketones by ceric ammonium nitrate <96JHC221>. 

Replacement of the ethanolamine head group is also well tolerated. Substitution with a cyclopropyl (243) [37], allyl (244) or propargyl group (245) [164] all led to an increase in binding affinity compared to AEA. Replacement of the head group with aromatics is also allowed. The phenyl derivative (246) retains affinity at the CBi receptor [37], whereas the 2-substituted A-methyl pyrrole (247) has a 2-fold improved affinity compared to AEA [167]. Interestingly, the 3-substituted furan derivative (23) that has micromolar affinity for the AEA transporter (see above) does not bind to the CBi receptor, but has good affinity for the CB2 receptor [167]. These results are summarised in Table 6.20. 

Metapone madagascarica M. new species W-PG Trail following Methyl pyrrole-2-carboxylate 140 [182]... 

The guanidinate complex (310) polymerizes LA at RT.893 Mn values increase with M0/Io ratios, but control is only moderate, with Mw/Mn typically >1.5. Transesterification occurs to a large extent as shown by NMR studies on the isolated PLA. Potentially tridentate 2,5-bis(N-arylimino-methyl)pyrroles have been explored as ancillary ligands for yttrium.894 Their reactions with... 

Similarly, 4-acetyl-2-(l,4-anhydro-D-ara fno-tetrahydroxybutyl)-5-methyl-pyrrole has been oxidized to 2-(4-acetyl-5-methylpyrrole-2)diglyoolaldehyde.S0... 

Schulten et al. [16] identified the following N-containing compounds in NH-N fractions separated from several soils by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) pyrrole (la), methyl pyrrole (lb), pyridine (IVa), methylpyridine (IVb), indole (Via), and benzothiazole (XI). The Roman numerals refer to the chem-... 

At higher temperatures retro-Diels-Alder reaction may also occur in the opposite sense to addition, as in the reaction of methyl pyrrole-1-carhoxylate with dimethyl acetylenedicarboxylate at 200°, which affords acetylene and the pyrrole triester (56). The decomposition of the suspected intermediate Diels-Alder adduct (11) at 170° has been separately established. Compounds 19 and 20 are intermediates in similar addition-elimination reactions leading to pyrrole-l,3,4-triesters, in which removal of acetylene from the system makes the reaction sequence effectively irreversible. 

Tetraphenylporphin (H2TPP) was prepared from pyrrole and benzaldehyde (25). The tetraphenylchlorin contamination was oxidized by use of 2,3-dichloro-5,6-dicyano-p-benzoquinone (26). Octaethylporphin (H2-OEP)was prepared by the method of Paine et al.(27) from 3,4-diethyl-2-ethoxy-carbony1-5-methyl-pyrrole (28). Zinc(II)-tetraphenylporphin (ZnTPP) was prepared by refluxing H2TPP and zinc acetate in dimethyl-formamide (29). ZnTPP was dissolved at a concentration of 10 -10 ... 

Reaction of N-acetyl-lO-bromodibenzazepine 51 with potassium ferf-butoxide yields the reactive intermediate 52 that reacts with N-methyl pyrrole 53 (X = NMe) used as a solvent to produce a mixture of Diels-Alder/retro Diels-Alder adduct 54 with the Michael by-product 55 (X = NMe, Scheme 10 (1994JHC293)). 

Similarly, methylation of pyrrolo-benzothiazepines 172 (Scheme 34, Section 2.3.1 (1994MI283)) and 307 (Scheme 66, Section 3.3.1.2 (2005FES385)) with methyl iodide in acetone in the presence of potassium carbonate proceeds regioselectively and produces N-methyl pyrrole derivatives as sole products. Methylation on the thiazepine ring nitrogen requires stronger base, i.e. potassium ferf-butoxide, to give dimethyl 174 and 311, respectively. 

Desmutagenic activity. Fresh plant juice, on agar plate at a concentration of 0.5 mL/ disc, was inactive on Salmonella typhimurium TA98 L Homogenate of the fresh root, at a concentration of 100 pL/disc on agar plate, was active on Salmonella typhimurium TA98 and TAIOO vs l,4-dinitro-2-methyl pyrrole mutagenesis ". 

Table 2 Difference of chemical shifts (AS, ppm) a of 31a and 8a carbons relative to carbons of furan and methyl pyrrole-2-carboxylate...

Positive sign denotes a downfield shift from furan and methyl pyrrole-2-carboxylate, respectively. Chemical shifts for furan are 143.6 (C-2), 110.4 (C-3) <1975CS211>, and for methyl pyrrole-2-carboxylate 122.0 (C-2), 115.1 (C-3) <1974JP21004>. 

Die Umsetzung von 3,4-Dinitro-l-methyl-pyrrol mit eincm UberschuB an sekundaren Aminen wie Piperidin oder Morpholin ergibt 2,3-Dipiperidino(b7.w. Dimorpholino)-l-me-thyl-4-nitro-2,3-dihydro-pyrrol (85 bzw. 87%)z. 

Das ziemlich einfach herstellbare 1 -Hydroxy- 1-piperidino-cyclopropan kann in Gegen-wart von Titan(IV)-chlorid in einer Variante der Mannich-Reaktion als Aquivalent von Cyclopropanon/Piperidin dienen nach der anzunehmenden in-situ-Umwandlung in 1-Cyclopropyliden-piperidinium-chlorid erfolgen Reaktionen z.B. mit 1-Trimethylsiloxy-cyclohexen zu 2-Oxo-l-(l-piperidino-cyclopropyl)-cyclohexan (63%) und mit 1-Methyl-pyrrol bzw. Indol zu l-Methyl-2-( 1-piperidino-cyclopropyl)-pyrrol (65%) bzw. 3-(l-Pipe-ridino-cyclopropyl)-indol (84%)2 ... 

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