Über eine neue Gewinnung von Pyrrol‐α‐aldehyden, sowie über stabile Tripyrrylmethane

Fischer, Hans; Ernst, Paul

doi:10.1002/jlac.19264470114

Cited by 18 publications

(3 citation statements)

References 5 publications

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“…The Gattermann reaction, like halogenation, is capable of displacing carboxyl groups from the pyrrole ring (145), thus transforming a carboxylic acid to the corresponding aldehyde. Houben-Hoesch synthesis, in which either an aliphatic or aromatic nitrile is substituted for the hydrogen cyanide in the Gattermann reaction, serves to introduce keto groups in the pyrrole nucleus (139).…”

Section: O ^Etc•mentioning

confidence: 99%

Recent Advances in the Chemistry of Pyrrole.

Baltazzi¹,

Krimen²

1963

Chem. Rev.

128

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Section: O ^Etc•mentioning

confidence: 99%

Recent Advances in the Chemistry of Pyrrole.

Baltazzi¹,

Krimen²

1963

Chem. Rev.

128

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“…The other attempt to prepare 1 -phenyl-5-tetrazolylcarboxaldehyde was suggested by the work of Fischer and Ernst (7) who synthesized pyrrole aldehydes from the corresponding halomethyl compounds through conversion to the anilinomethyl derivatives followed by permanganate oxidation and hydrolysis of the resulting Schiff base. Thus l-phenyl-5-chloromethyltetrazole was reacted with aniline, using the method of Harvill and his co-workers (2) for the preparation of 5-N-substituted aminomethyltetrazoles, to give a 52% yield of 1-phenyl-5-anilinomethy ltetraz ole.…”

Section: C02etmentioning

confidence: 99%

Studies in Tetrazole Chemistry. Iii. Some Reactions of 1-Phenyl-5-Chloromethyltetrazole

Jacobson¹,

Kerr²,

Amstutz³

1954

J. Org. Chem.

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The preparation of l-phenyl-5-chloromethyltetrazole (I) was first disclosed in a patent (1) issued to Harvill and Herbst covering the preparation of 1-substituted-5-a-halogen alkyltetrazoles. In a more recent publication (2) these authors report the preparation of a wide variety of -haloalkyltetrazoles and the reaction of these compounds with various reagents to give amino and hydroxy derivatives. They state that the 5-haloalkyltetrazoles react like typical alkyl halides. This observation has been generally substantiated in an investigation of a number of reactions of l-phenyl-5-chloromethyltetrazole in this laboratory.Although the structure of l-phenyl-5-chloromethyltetrazole together with its irritant action on the skin may suggest analogies with compounds of the benzyl chloride type, such a comparison does not appear to be valid. This tetrazole reacts immediately with sodium iodide in acetone solution, precipitation of sodium chloride being essentially complete in less than one minute. In comparison, several minutes reflux of this compound in alcoholic silver nitrate solution gave no evidence of silver chloride precipitation. These results indicate

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“…However, it methods, the bromination of four 5-bromo-5'-had suggested that 5'-bromo~nethylpyrromethenes methylpyrromethenes under various conditions was would be favoured if 2-methylpyrroles were more followed by the 'Hmr signals of the CH2Br (or completely converted to 2-bromomethylpyrroles CH20Me) and bridge C H groups. The best results before condensing to pyrromethenes; thus 2-methylwere obtained in acetic acid after 45 min on the 5-tert-butoxycarbonylpyrroles were brominated to 5-bromo-5'-bro~nomethylpyrromethenes (12 2-carboxylic acids 2, for both a hydroxymethylpyrrole (13) and an ethoxymethylpyrromethene (66) had been converted into their bromomethyl derivatives by hydrogen bromide in acetic acid. This was not considered too promising because the acetoxymethyl groups might well be displaced by bromine before they were locked on as bromomethyl, a process requiring hydrogen bromide formed by the brominative displacement of the carboxyl group.…”

mentioning

confidence: 99%

A new route to 5-bromo-5′-bromomethylpyrromethenes

Rowold¹,

MacDonald²

1978

Can. J. Chem.

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. 56,1907 (1978). Esters of hitherto inaccessible 5-brorno-5'-bromornethylpyrrornethenes, with alternating acetic acid (or methyl) and propionic acid groups in the (3 positions, are obtained by brorninating the appropriate 5-acetoxymethylpyrrole-2-carboxylic acids in ethanol-free chloroform a t r 10°C. The brornornethylpyrrornethenes give the corresponding rnethoxymethylpyrrornethenes in methanol at room temperature.AREND ROWOLD et S. FERGUSON MACDONALD. Can. J. Chem. 56, 1907Chem. 56, (1978. On a pu obtenir des esters des brorno-5 brorno-5' rntthylpyrrornCthines qui Ctaient jusqu'k present inacessible et qui possedent en alternance en position (3, des groupes acide acttique (ou rntthyle) et des groupes d'acide propionique; on a rCalise cette prtparation en faisant la brornuration des acides acCtoxyrnCthyl-5 pyrrolecarboxyliques-2 appropriCs dans du chloroforrne sans ethanol a une temperature 5 10°C. Les brornornethylpyrrorn6th6nes conduisent a u rnCthoxyrnCthylpyrrornCth6nes correspondants par rCaction avec le mCthanol a la ternptrature ambiante.[Traduit par le journal]The unavailability of some 5-bromo-5'-bromo-steam bath, using 2 mol of bromine with 3h and 3k, lnethylpyrromethenes has limited the generality of and 4 mol with 3b and 3e. Complete bromination Johnson and co-workers (1) synthesis of porphyrins could not be forced because of the instability of the from 1'-bromo-8'-methylbiladienes-a,c (cf. refs. 2 bromomethyl derivatives. The crude products, conand 3). We were particularly interested in esters of taining 5'-methyl-and 5'-bromomethylpyrrometh4a and its isomers, which were also promising inter-enes, were treated with methanol t o convert the mediates for the synthesis of polypyrranes related to latter into more stable 5'-methoxymethylpyrrothe uroporphinogens (4, 5). A preliminary communi-inethenes, and those from 3b and 3e were then discation (5) covers the work described below.solved in chloroform-methanol (9: 1) and filtered 2-Methylpyrroles, and their 5-carboxy-(ref. 60) through alumina to remove by-products. The 'Hmr or 5-tert-butoxycarbonyl derivatives (7), are bro-spectra of the products from 3b, 3e, 3h, and 3k then lninated to 5-bromo-5'-methylpyrromethenes with indicated conversions of < 30, < 30, 65, and 85x, alternating P substituents, e.g. 3a. 5-Bromo-5'-respectively. Only the methoxymethylpyrromethene bromomethylpyrromethenes are obtained in the L;k ((60%) was obtained crystalline, and this is much same way or, with greater formal generality, by bro-more readily obtained otherwise (see below). Other minating 5-bromo-5'-methylpyrromethenes. How-routes to 4a and 4d or their esters were obviously ever, both of these are uncertain routes to the bro-required, but the ester 3k was evidently more readily momethylpyrromethenes when there are propionic brominated than the above mentioned free acid 3i.acid groups in the P positions. In particular, the Routes to 4a and 4d or their esters based on the brominations of 3d, 3e (4), and of 3 j (8) had failed, bromination of 2-methylpyrroles were then ...

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Über eine neue Gewinnung von Pyrrol‐α‐aldehyden, sowie über stabile Tripyrrylmethane

Cited by 18 publications

References 5 publications

Recent Advances in the Chemistry of Pyrrole.

Recent Advances in the Chemistry of Pyrrole.

Studies in Tetrazole Chemistry. Iii. Some Reactions of 1-Phenyl-5-Chloromethyltetrazole

A new route to 5-bromo-5′-bromomethylpyrromethenes

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