Mannich reaction of imidazoles

Abstract

The Mannich Reaction of Imidazoles 883 acidified with methanolic hydrogen chloride and the salt was crystallized from EtOH-EtOAc to give 1.12 g, mp 211-212°d ec, and 0.344 g, mp 207.5-5-208.5°dec (23.9%), of 29 hydrochloride. An analytical sample was obtained: mp 209-210°d ec; uv (EtOH) Xmax 219 mM (« 17,700), 276 (8550), 283 (8700), and 293 (inflection, 7650); ir (Nujol) 1640 cm-1 (C=N+); mass spectrum m/e (rel intensity) 228 (100), 213 (6.5), 200 (34), 199 (34), and 171 (16); nmr [(CD3)2S0-D20] 1.42 (t, 3,

The regioselective synthesis of 2-substituted [[(α-aryl-(α′-amino)]methyl]imidazoles through a catalyst-free, one-pot, three-component reaction: scope and limitations

“…The exclusive formation of 2-substituted imidazole in our case, is strong evidence in favor of the involvement of the imidazolium ylide as an intermediate in the mechanistic pathway because normal Mannich-type substitution would be expected to lead to 4-or 5-substituted imidazoles. 26 The suggested mechanism is shown in Scheme 2 in which imidazolium ylide …”

Dimethylamino-functionalised and N-heteroaryl-substituted titanocene anticancer drugs: synthesis and cytotoxicity studies

“…The synthesis of 2,4-[bis (N′,N′-dimethylaminomethyl)]-N-methyl pyrrole was synthesised from N-methyl pyrrole based on the typical Mannich reaction, following the conditions found in the literature [27].…”

“…The use of aryl lithium in the synthesis of other metallocenes is well known [26][27][28][29][30], and it has recently been used for the synthesis of achiral titanocene dichlorides [13,14]. This time, the carbolithiation method led to the synthesis of a new group of titanocenes that contain stereo centres (5a-c).…”

“…UV/Vis spectra were recorded on a Unicam UV4 Spectrometer, while CHN analysis was done with an Exeter Analytical CE-440 Elemental Analyser. Synthesis 6-N,N-Dimethylamino fulvene and 2,4-[bis(N′,N′-dimethylaminomethyl)]-N-methyl pyrrole were synthesised according to the already published procedures [26,27] in 82 and 98% yield, respectively.…”

2,8-Dimethyl-5,11-dipropyl-1,4,5,6,7,10,11,12-octahydroimidazo[4,5-h]imidazo[4,5-c][1,6]diazecine Hexahydrate

“…The Mannich reaction, which is one such powerful and simple process, is a one-step method for attaching aminomethylene groups to the imidazole ring (Stocker, Kurtz, Byron & Forsyth, 1970). The reaction of aldehydes, in particular formaldehyde, with different substrates and conditions has been used widely in organic synthesis.…”