Reductive amination of carboxylic acids and [11C]magnesium halide carboxylates

Consecutive alkylation–reduction reactions of 2 H -1,2,3-benzothiadiazine 1,1-dioxide derivatives. Synthesis of 2-alkyl-, 3-alkyl-, and 2,3-dialkyl-3,4-dihydro-2 H -1,2,3-benzothiadiazine 1,1-dioxides

“…However, our attempts to prepare N(2),N(3)-dialkylated product 7a by N(3)-alkylation of 5a, failed. Thus, our results suggest that the synthesis of the new N(2),N(3)-dialkylated 3,4-dihydro-2H-1,2,3-benzothiadiazine 1,1-dioxides (7,8) should pass through intermediates of type 6.…”

“…In this case formation of 10 was not observed, 4a was isolated in 58% yield after recrystallization (Scheme 2, Method E). Reductive amination of carboxylic acids, i.e., the synthesis of tertiary amines from carboxylic acids and secondary amines (with NaBH 4 , in the presence of quaternary ammonium salts) was described by Perrio-Huard et al 8 When TFA is applied as the carboxylic acid, a similar introduction of a 2,2,2-trifluoroethyl moiety to the nitrogen atom is described for aromatic, 9,10 benzyl-, 10 and cycloalkyl-10,11 amines in the presence of NaBH 4 or LiAlH 4 . However, to the best of our knowledge, aminals similar to 10 have not been described in the literature when starting from TFA and an amine, under reductive conditions.…”

Cobalt‐Catalyzed Reductive Alkylation of Amines with Carboxylic Acids

“…[5,6] Metal-catalyzed direct reduction of imines or amides by using varioush ydride sources including molecular hydrogen fort he synthesis of secondary alkyl or aryl amines is aw ell-established method but it requires an additional step to prepare carbonyl derivatives. [8] Direct reductive alkylation of amines startingf rom highero xidized hydrocarbons, such as carboxylic acids, using molecular hydrogen is av ery attractive methoda nd it avoidst he usage of toxic organometallic reagents. [8] Direct reductive alkylation of amines startingf rom highero xidized hydrocarbons, such as carboxylic acids, using molecular hydrogen is av ery attractive methoda nd it avoidst he usage of toxic organometallic reagents.…”

Synthese von 11C‐, 18F‐, 15O‐ und 13N‐Radiotracern für die Positronenemissionstomographie

“…11 C]Carboxymagnesiumhalogeniden wurde beschrieben; [134,135] die Reaktion wurde durch Mikrowellenbestrahlung beschleunigt (Schema 28). [136] Mög- Synthese von PET-Tracern Angewandte Chemie führen des "nichtnatürlichen" Fluoratoms kann unbekannte Auswirkungen auf die biologischen Eigenschaften eines Moleküls haben, [143] und es ist schwierig, einen direkten Vergleich zwischen den biologischen Eigenschaften der nichtfluorierten Stammmoleküle, die möglicherweise im Detail bekannt sind, und dem 18 F-markierten Derivat anzustellen.…”