AGROCHEMICALS
Figure 2 - Average number of steps & technologies used in agrochemical synthesis by product class
fluorination etc .) used in the manufacture of AIs by the year of first AI introduction . This shows that the number of steps has increased from generally less than ten on average before the 1990s to generally over ten in more recent years , although with significant variation .
This analysis is based on a proposed method of synthesis as outlined in AgbioInvestor ’ s AgbioChem service , which displays the synthetic route and technologies used for 357 commercially significant agrochemical AIs ; the true commercial routes may vary by AI , company , etc . It should also be noted that the number of steps for an AI might drop if new methods of synthesis are discovered .
Technology usage
Figure 1b takes shows the fiveyear-average percentage of AI introductions in each year that are synthesised using different technologies . A broader suite of technologies is used in agrochemical synthesis than ever before . In the 1950s , fluorination and bromination were not important , but since 2000
they have been used for more new AIs , while nitrogen chemistry and phosgenation have been used less .
Further to this , using AgbioChem data we can analyse the number of steps and technologies used in the key agrochemical classes ( Figure 2 ). The key findings are outlined below by sector :
• Fungicides : SDHI fungicides ( mainly pyrazolecarboxamides ) and strobilurins ( e . g . methoxyacrylates , methoxycarbamates ) have the most steps on average
• Herbicides : Sulfonylureas ( e . g . nicosulfuron ), triazolinones ( e . g . sulfentrazone ) and HPPD inhibitors ( e . g . mesotrione ) all have a high average number of steps
• Insecticides : Diamides ( e . g . Rynaxypyr ) and ketoenols ( e . g . spirotetramat ) have a high number of steps Most products with a low number of steps are older low-priced commodities , e . g . glyphosate , atrazine , 2,4-D . However , a lot of value is associated with these products due to the high volumes used . Almost all the more complex AIs ( in terms of number of steps ) are associated with low volume and sales markets , but there is a relatively high value for products in the ten- to 15-step range with a low volume used .
In addition , we can get insights into the ring types and commercial situation for different ring types . As shown in Figure 3 , value , volume and price are based on usage of agrochemicals with this ring type and do not reflect the specific price of these rings . Ring value and ring volume are calculated using a percentage based on the number of rings and ring types for each synthetic route .
This analysis shows that pyridines and chlorobenzenes are important in terms of value and volume in the agrochemical industry . Anilines ( such as acetochlor , metolachlor and carbendazim ) and 1,3,5-triazines ( like atrazine , terbuthylazine and ametryn ) are important in volume terms but very low-priced .
Pyridines focus
To investigate more in depth , we analysed a specific ring type , pyridines , to see which classes are important in value and
JAN / FEB 2025 SPECCHEMONLINE . COM
17