Pesticide Synthesis Handbook

ABOUT THE AUTHOR Dr. Thomas A. Unger obtained his Bachelor of Science degree in Chemical Engineering at the Massachusetts Institute of Technology (M.I.T.), and his Doctor of Science degree in Chemical Engineering in 1958, also at M.I.T. From 1960 to 1982 he was Manager and Director of Rhodia S.A. (affiliate of Rhone Poulenc) chemicals, pesticides, pharmaceuticals, veterinary products, synthetic fibers, consumer products, minerals. He is also a Director of the Brazilian Association of Chemical industry. From 1983 onwards he has been a consultant to the pesticide, chemical ~ d petrochemical industries as well as to financial institutions. In 1992, he founded and is president of Prochrom Industrias Quimicas S/A. Prochrom is one of the largest manufacturers of intermediates and active ingredients for crop protection products in Latin America. He is a member of the New York Academy of Sciences, and serves on the Board of Administration of several chemical and plastics manufacturers. PREFACE Pesticide synthesis is based upon obtaining a certain function and constructing the rest of the molecule that goes around that function. Pesticides are classified in families according to the leading function. / For instance amide pesticides all contain the function / carbamate pesticides contain R1 R3--C--.N II \ 0 R1 R3--O---C--N O R2 and so on. Though the main function is important for the efficiency and mode of action of the pesticide, it is by no means sufficient as such. It is the radicals and chemical groups surrounding the main function which make all the difference between a great product and a mediocre one, which is why it is difficult to design a successful pesticide. Success in the pesticide industry still depends upon the trial and error screening of many products, before a great product is found. A successful pesticide is imitated, in one way or another, thus giving rise to a family of products. That is why over 98% of all pesticides can be classified in one of the main families of products, the remaining being products one-of-a-kind. While the synthesis of pesticides varies considerably even within the same family of products, certain general principles hold true for each family which helps in understanding the synthesis path. This is why the products are grouped together by the main function. Finally, some pesticides have several of the main functional groups in the molecule and can be classified within more than one family. HOW TO USE THIS HANDBOOK The main objective of this handbook is to describe the basic synthesis route(s) for the manufacture of pesticides. VII viii Preface Important sidelines are a list of the main raw materials and intermediates used in the synthesis of pesticides, as well as a list of all pesticides which are made using a given raw material or intermediate. For this purpose there are five Appendices. I. Generic Names The Generic Name Appendix indicates the chemical function of the compound. If the compound has more than one function, all functions are indicated. In this case, the synthesis route of the compound is found under the first function indicated in this Appendix. Example: Quizalofop---This compound is listed as phenoxy carboxylic acid, quinoxaline. Phenoxy carboxylic acid is the first chemical function in the listing, indicating that the synthesis route of quizalofop is found in the chapter under phenoxy carboxylic acids in the main text. II. Trade Names When only the trade name of the product is known the corresponding generic name is found in this Appendix. Example: Targa--Corresponding generic name is quizalofop. HI. Raw Materials and Intermediates This appendix lists all pesticides, the synthesis of which uses a given raw material or intermediate. For example, the synth