Methods for the batch scale up of DABAL-Me-3 promoted direct ester to amide synthesis have been demonstrated at 10-100 g scales using a tert-amide model compound. Procedures for 20 g scale couplings in standard laboratory glassware and up to 0.1 kg in industry-standard jacketed glass reactors in near quantitative yields are given. A derivative of the anticancer agent Imatinib (Gleevec) has been synthesized on a 26 g scale (98% yield, >98% purity) establishing DABAL-Me-3 as a potential alternative for the synthesis of amides in API scale preparations. Continuous flow methodology provides a method for larger scales (productivities of >50 g h(-1)). In addition, nitriles were coupled to primary amines and hydrazines with DABAL-Me-3, resulting in the clean formation of free amidines (16 examples) and amidrazones.
Reynaud,P. et al., Bulletin de la Societe Chimique de France, 1978, vol. <II>, p. 449 - 456
作者:Reynaud,P. et al.
DOI:——
日期:——
Sulfated tungstate catalyzed activation of nitriles: addition of amines to nitriles for synthesis of amidines
作者:Sachin D. Veer、Kamlesh V. Katkar、Krishnacharya G. Akamanchi
DOI:10.1016/j.tetlet.2016.07.073
日期:2016.9
the synthesis of amidines by direct nucleophilic addition of amines to nitriles using sulfated tungstate as heterogeneous catalyst is described. Highlight of the method is its applicability for the synthesis of amidines using a wide variety of amines including ammonia as ammonium acetate and nitriles. Catalyst is mildly acidic, stable, easy to prepare and separate from the reaction mass.