Aminomethylierung. Eine Studie zur Aufklärung und Einordnung der Mannich‐Reaktion

Hellmann, H.; Opitz, G.

doi:10.1002/ange.19560680803

Cited by 113 publications

(18 citation statements)

References 15 publications

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“…1. Etherifying reagent HMMAHC was prepared from hydroxymethyl dimethylamine (a) in strong acid medium, and it would be converted into dimethylamino carbonium salt intermediate (b) and methylene iminium salt intermediate (c) (reactions 1) according to Mannich reaction (Arend, Westermann, & Risch, 1998;Hellmann & Optiz, 1959). Intermediates b and c could exist under non-water condition.…”

Section: Resultsmentioning

confidence: 99%

Preparation and application of a new cationic starch ether – Starch–methylene dimethylamine hydrochloride

Jiang

Zhang

et al. 2010

Carbohydrate Polymers

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Section: Resultsmentioning

confidence: 99%

Preparation and application of a new cationic starch ether – Starch–methylene dimethylamine hydrochloride

Jiang

Zhang

et al. 2010

Carbohydrate Polymers

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“…The failure of secondary amines in the condensation may be due to unfavorable competition of the amine with the aryl-sulfonylacetic acid for the aldehyde as a result of steric factors. Furthermore, the use of aromatic aldehydes may lead to Schiff bases rather than to the postulated aminomethanols, since the former are more stable than the latter under the conditions of the reaction (17,(19)(20)(21). This conclusion may be supported by the work of Balasubramanian and Baliah (le), who reported that acetaldehyde-ammonia and w-benzenesulfonylaceophenone gave only 2,4-bis( benzenesulfonyl) -1,5diphenyl -3methyl -1,5pentanedione.…”

Section: Resultsmentioning

confidence: 99%

“…This conclusion may be supported by the work of Balasubramanian and Baliah (le), who reported that acetaldehyde-ammonia and w-benzenesulfonylaceophenone gave only 2,4-bis( benzenesulfonyl) -1,5diphenyl -3methyl -1,5pentanedione. The order of addition may also account for this product (17,21). The conclusions drawn in this study are presented in the form of a tentative mechanism proposal (Scheme I).…”

Section: Resultsmentioning

confidence: 99%

Application of Mannich Reaction to Sulfones II

Nobles

Thompson

1965

Journal of Pharmaceutical Sciences

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“…The results for 4 proved that the structure was N-(3-oxobutyl)cytisine, which was probably formed through a Mannich reaction [4,5].…”

Section: Reaction Of Cytisine With Formalinmentioning

confidence: 99%

Reaction of cytisine with formalin

2006

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547.945The reaction of cytisine with formalin in various solvents was studied. Methylene-bis-cytisine was produced in addition to the expected N-methylolcytisine in all solvents except acetone, in which N-(3-oxobutyl)cytisine was produced.The combination of various natural fragments in a single molecule is interesting regarding their mutual effect on the biological activity of the resulting compounds. In this regard, N-methylolcytisine (1) might be an interesting synthon [1].The preparation of 1 by reaction of cytisine (2) with formalin (35%) in ether and the formation of bis-cytisinomethane (3) by the reaction in absolute alcohol with added Ca(OH) 2 have been reported [1].The use of ether as the solvent for production of 1 was impractical because of the poor solubility of cytisine in it. Therefore, we compared the reaction of cytisine with formalin (30%) in various solvents (ether, methanol, ethanol, hexane, chloroform, water, dioxane, acetone).The reaction mixture of cytisine and formalin in the appropriate solvents was held at room temperature for 4-6 h. Chromatographic monitoring showed that a certain amount of unreacted cytisine remained in all reactions regardless of the solvent and that a product with R f 0.7 was formed.The reaction in ether produced crystals of 3a, mp 131-132°C; in acetone, 115°C (4), in other solvents, 213-215°C (3). The mass spectrum of the last had peaks for a molecular ion with m/z 392 and for ions with m/z 204, 203, 190, 160, 159, 147, and 146, which confirmed the structure of 3 as bis-cytisinomethane.According to the literature [1], it can be hypothesized that N-methylolcytisine forms in ether, for which mp 110-114°C was reported [1].The IR spectrum of 3a obtained from the reaction in ether contained a broad absorption band for active H with a maximum at 3490 cm -1 . However, the melting point of 3a was higher than that found for 1. The PMR spectrum showed that 3a and 3 had the same spectrum. An x-ray structure analysis proved that 3a was a crystal hydrate of 3 [2].Thus, all attempts to prepare 1 were inconclusive, probably due to the high reactivity of 1, which led to its further reaction with cytisine and formation of the bis-product 3, which was not only the synthetic product but also a natural compound (12,12′-methylenedicytisine) that was isolated from Maackia amurensis [3].

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Aminomethylierung. Eine Studie zur Aufklärung und Einordnung der Mannich‐Reaktion

Cited by 113 publications

References 15 publications

Preparation and application of a new cationic starch ether – Starch–methylene dimethylamine hydrochloride

Preparation and application of a new cationic starch ether – Starch–methylene dimethylamine hydrochloride

Application of Mannich Reaction to Sulfones II

Reaction of cytisine with formalin

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