Discovery and development of a commercial synthesis of azafenidin
A commercial synthesis of the DuPont herbicide azafenidin is described. Discovery of a novel synthesis of the triazolinone ring system and a practical, environmentally benign process to 5-cyanovaleramide were critical breakthroughs in enabling azafenidin to be manufactured at an acceptable cost. The process began with the selective hydrolysis of DuPont's nylon intermediate, adiponitrile, to 5-cyanovaleramide. This was converted via Hofmann rearrangement and Pinner-type cyclization to afford the key amidine carboxylate intermediate containing both carbon atoms of the triazolinone ring. The preservation of all six carbon atoms of adiponitrile set up a 2 + 3 cyclocondensation with arylhydrazines, which replaced a costly 4 + 1 cyclocondensation of an amidrazone with phosgene or a phosgene surrogate used in the original route. This new triazolinone process was optimized to afford the commercial product in a highly efficient and economical fashion.
Shapiro, Rafael,DiCosimo, Robert,Hennessey, Susan M.,Stieglitz, Barry,Campopiano, Onorato,Chiang, George C.
p. 593 - 598
(2013/09/07)
Process to prepare herbicidal bicyclic triazoles
This invention includes compounds of Formula II and IV and a process for preparing Formula I compounds by first preparing the compounds of Formula IV and then further reacting to form the compounds of Formula II and further reacting to prepare the compounds of Formula I wherein Q, Z, R2 are as defined within. STR1
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(2008/06/13)
Herbicidal substituted bicyclic triazoles
Substituted bicyclic triazole compounds essentially as shown in Formula I, agricultural compositions containing them, and the method of use of these compounds as herbicides for the control of undesired vegetation in crops STR1
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(2008/06/13)
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