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Potassium compounds pyrrole

Treatment of pyrrole, 1-methyl-, 1-benzyl- and 1-phenyl-pyrrole with one mole of A -bromosuccinimide in THF results in the regiospecific formation of 2-bromopyrroles. Chlorination with IV-chlorosuccinimide is less selective (8UOC2221). Bromination of pyrrole with bromine in acetic acid gives 2,3,4,5-tetrabromopyrrole and iodination with iodine in aqueous potassium iodide yields the corresponding tetraiodo compound. [Pg.50]

Under microwave irradiation several azaheterocycles (i.e. pyrrole, imidazole, indole and carbazole) can react remarkably fast with alkyl halides to give, exclusively, N-al-kyl derivatives (Eqs. 32 and 33) [45, 46]. Such reactions have been performed simply by mixing an azaheterocycle compound with 50% excess alkyl halide and a catalytic amount of TBAB. The reactants were absorbed either on a mixture of potassium carbonate and potassium hydroxide or on potassium carbonate alone and then irradiated in a domestic microwave oven for 30 s-10 min. [Pg.162]

As with the reaction of pyrroles, diazoles and triazoles react with propargyl bromide to yield TV-substituted products and, depending upon the base strength, either TV-prop-2-ynylazoles or allenic derivatives are formed [30]. Generally, with potassium carbonate under soliddiquid two-phase conditions at room temperature in the absence of a solvent, the prop-2-ynyl compounds are formed as sole products, whereas with solid potassium hydroxide at elevated temperatures the allenes are obtained as the major products. Benztriazole produces a mixture of the N1- and N2-prop-2-ynyl, and N2-allenic derivatives, whereas with potassium hydroxide only the N -allenic derivative is obtained. The alkynes readily isomerize to the allenes in the presence of base and the quaternary ammonium salt, or upon treatment with methanolic sodium hydroxide. A series of l-(alk-2-ynyl)imidazoles have been prepared, as intermediates in the synthesis of imidazopyridines [31 ] and the reaction of 3-hydroxymethylpyrazoles with propargyl bromide leads to pyrazolooxazines [32]. [Pg.200]

The possibility of acetylating the pyrrole nitrogen atom of 9a was investigated. The reaction was performed in the presence of different bases, and the highest yield of the corresponding compound 9b was achieved for potassium tert-butoxide. As should be expected, even trace amounts of this compound are absent from the acylation products of thienopyrrole 9a under Friedel-Crafts conditions <20020L387>. [Pg.14]

When pyrrole is treated with potassium (but not with sodium) or boiled with solid potassium hydroxide, potassium pyrrole C4H4NK is formed, which is the starting point for AT-deriva lives of pyrrole, since reaction of the potassium with halogen of organic compound and with carbon... [Pg.1390]

Two routes for the synthesis of a four-terminal wire compound based on a central porphyrin unit are presented in Scheme 10.25 [13b], In one route, the tetrabro-mide 75 was treated with potassium thioacetate, which resulted in the substitution product 76. Alternatively, reaction of aldehyde 77 with pyrrole 78 at room temperature using mixed acid catalysis conditions provided 76 after oxidation with DDQ. [Pg.365]

Azaferrocene (206) has been prepared by the reaction of sodium pyrrole, cyclopentadienylsodium, and ferrous chloride,157 or better by the reaction of potassium pyrrole with cyclopentadienyliron dicarbonyl iodide.158 It has been found159 that dioxane is a better solvent than benzene for this latter reaction. This reaction has also been applied to 2,4- and 2,5-dimethylpyrrole,158 3-acetyl-2-methyl-and 3-acetyl-2,4-dimethylpyrrole,160 and 2-methylpyrrole.159 The 2-methylazaferrocene from this latter pyrrole has been resolved with (—)6,6 -dinitrodiphenic acid.159 A compound (207) believed to be an intermediate in the formation of azaferrocenes has been isolated.161... [Pg.43]

Compound 2 was furthermore employed in the preparation of NH-linked Pc-porphyrin arrays [60]. The reaction between the amino-functionalized porphyrin 8 and 4-iodophthalonitrile using Buchwald-Hartwig amination conditions (Pd(OAc)2/ rac-BINAP (BINAP = 2,2/-bis(diphenylphosphino)-l,l/-binaphthyl) as the catalytic system) in the presence of potassium fe/7-butoxide, delivered the entities connected either at the meso-phenyl group (9 in Fig. 7) or at the /1-pyrrolic position [61]. [Pg.8]

There are few references to dioxinopyrroles which are compounds which do lend themselves to systematic study. The lactam acetal of 1-methylpyrrole (288) reacts with aldehydes in anhydrous ether (or in the absence of solvent) at room temperature to give the tetrahydro-l,3-dioxino[4,5-6]pyrroles (289) (Scheme 21). These lose one molecule of aldehyde when treated with alcoholic potassium hydroxide to yield the benzhydrols (290) <83IJC(B)1079>. [Pg.270]

The alkylation of pyrroles 131 with epichlorohydrin using potassium carbonate as a catalyst affords l-(2-oxiranyl-methyl)-l/7-pyrroles 132 in modest to high yields (Equation 22) <2002BMC2511>. A similar synthetic route led to indole derivatives 133 (Equation 23). Both compounds 132 and 133 are precursors of isopropanolamines, potential anti-HIV-l-PR agents. [Pg.65]

Heterocyclic compounds containing a nitrogen atom commonly undergo N-alkylation or C-alkylation. N-Methyl pyrrole can be prepared by interaction of methyl iodide with potassium pyrrole (40%). N-Carbethoxy pyrrole is made from chloroformic ester and potassium pyrrole. The C-alkylation of pyrroles has been discussed. 3-Alkylindoles are made by the alkylation and decarboxylation of indole-2-carboxylic acid. The conditions for alkylation of pyrrolidine are analogous to those employed for the alkylation of a secondary amine. Thus, pyrrolidine on treatment with n-butyl bromide and potassium hydroxide in boiling benzene is con-... [Pg.423]

The only six membered hetero-cyclic compound which we shall consider is the one analogous to pyrrole. It contains a hetero-cyclic ring of five carbons and one nitrogen just as pyrrole contains four carbons and one nitrogen. This compound is known as pyridine. That pyridine is a six membered ring analogous to pyrrole is proven by the fact previously referred to (p. 854), that potassium pyrrole by the action of chloroform takes up an additional carbon and yields a chlorine substitution product of pyridine. [Pg.856]


See other pages where Potassium compounds pyrrole is mentioned: [Pg.854]    [Pg.82]    [Pg.119]    [Pg.85]    [Pg.1010]    [Pg.85]    [Pg.684]    [Pg.191]    [Pg.90]    [Pg.209]    [Pg.309]    [Pg.236]    [Pg.242]    [Pg.251]    [Pg.289]    [Pg.413]    [Pg.52]    [Pg.361]    [Pg.66]    [Pg.48]    [Pg.7]    [Pg.403]    [Pg.236]    [Pg.242]    [Pg.251]    [Pg.289]    [Pg.35]    [Pg.187]    [Pg.390]    [Pg.402]    [Pg.139]    [Pg.219]    [Pg.273]    [Pg.7]    [Pg.20]   
See also in sourсe #XX -- [ Pg.61 ]




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