A novel alkylation procedure using MW irradiation for the synthesis of 1,2,3-trisubstituted 1,4,5,6,7,8-hexahydro-1,3-diazocinium salts from their corresponding 1,2-diaryldiazocines

作者：Ramirez Maria A; Ortiz Gisela M; Salerno Alejandra; Perillo Isabel A; Blanco Maria M^*

来源：Tetrahedron Letters, 2012, 53(11): 1367-1369.

DOI：10.1016/j.tetlet.2012.01.009

• Cyclic amidinium salts
• Cyclic amidines
• Ethyl polyphosphate
• N-alkylation
• Microwaves

In this work, we describe the synthesis of a series of 1,2,3-trisubstituted-1,4,5,6,7,8-hexahydro-1,3-diazocinium salts (1) by alkylation of the corresponding 1,2-diaryl-1,4,5,6,7,8-hexahydro-1,3-diazocines (2). Compounds 2 were obtained by ethyl polyphosphate-promoted cyclocondensation of N-aroyl-N%26apos;-aryl-pentamethylenediamines (3). Reaction of compounds 2 with alkyl iodides led to 1,2,3-trisubstituted 1,4,5,6,7,8-hexahydro-1,3-diazocinium iodides (1), a new family of cyclic amidinium salts. The best yields for the alkylation were achieved using a mixture of DCM-DMSO (10:1) as solvent. The reaction times of both, the cyclocondensation of compounds 3 and the reaction of 2 with alkyl halides, are dramatically decreased when using microwave irradiation.

• 出版日期2012-3-14