Abstract
The aim of this study was to develop an optimized process for the manufacturing of
hexazinone and to validate laboratory results on a larger scale, in this case a miniplant.
Patent protection on hexazinone has expired and the objective of this study was
to improve on the known commercial process to enable the cost-effective
manufacturing of hexazinone. The generic market is highly competitive and
hexazinone can be sourced from several suppliers at low cost. Ownership of improved
technology for the production of hexazinone can give Dow AgroSciences a
competitive advantage in the generic market. Various routes for the manufacture of
hexazinone are reviewed and important aspects of scale-up is considered and
summarized.
The known commercial five-step synthesis was optimized on a laboratory scale, using
experimental design where applicable. The optimized procedures were scaled to the
mini-plant.
Significant improvements over patent results were realized for the process efficiencies.
This is in particular true for the synthesis of N-ethoxycarbonyl-N,N,Ntrimethylguanidine
in step 3. Employing experimental design to optimize the reaction
was instrumental in meeting the objective of the study. Higher overall yields lead to
substantial cost savings because of more efficient raw material conversion to value
adding products.
Die doel van hierdie studie was om die vervaardigingsproses vir heksasinoon te optimizeer. Die geldigheid van die laboratorium resultate is bevestig op ‘n groter skaal, in hierdie geval, op ‘n loodsaanleg met ‘n vyftig liter kapasiteit. Patente op die bekende vervaardigingsproses van heksasinoon het verval. Die mark vir generiese produkte is hoogs kompeterend en heksasinoon kan teen lae koste aangekoop word van verskeie vervaardigers. ‘n Betekenisvolle verbetering op die bestaande tegnologie kan aan Dow AgroSciences ‘n kompeterende voordeel besorg in die generiese heksasinoon mark. Die studie gee ‘n oorsig oor verskeie roetes vir die vervaardiging van heksasinoon en belangrike aspekte van opskalering.
Die bekende vyf-stap sintese van heksasinoon is suksesvol geoptimiseer in die laboratorium met behulp van eksperimentele ontwerp. Die optimum kondisies is bevestig op ‘n loodsaanleg.
Die gebruik van eksperimentele ontwerp om die vervaardigingsproses te optimiseer, het gelei tot belangrike verbetering in die tegnologie. Die totale opbrengs van die vyf-stap sintese oorskry gedokumenteerde waardes. Die geoptimiseerde proses kan lei tot betekenisvolle besparings deur die effektiewe omskakeling van uitgangstowwe na ‘n waardevolle produk.
Prof. F. Van Heerden