Geigy herbicides

Another example from the Ciba-Geigy group concerns the chemoselective reductive dehalogenation of 2,2,4-trichlorobutanal to 2,4-dichlorobutanol (Eqn. (4)), a herbicide intermediate (Bader et al., 1996). 

A fascinating example of enantioselective catalysis for agrochemicals is the production of a well-known herbicide of Novartis (formerly Ciba Geigy), metolachlor (Trade name Dual... 

Anonymous Aatrex Herbicide Technical Bulletin, Geigy Agric Chem Div, Ciba-Geigy, Ardsley, NY, June 1971... 

The first triazine was discovered in 1952 at J.R. Geigy, Ltd. in Switzerland. Today one or more of the triazine herbicides are registered in more than 100 countries around the world and are key to the production of more than 50 crops. Table 1.2 shows the major triazine herbicides today and their key uses. 

Figure 1.7 Best management practices reduce herbicide runoff (from Ciba-Geigy Technical Report 10-92).

For Geigy, the beginning of the herbicide project in 1952 was an ambitious venture in a new field of research. Dr. Albert Gast was given the responsibility for biological evaluation of the herbicides, and Dr. Enrico Kniisli, who had joined the company in 1952, was responsible for the systematic synthesis of potential new herbicides. A good description and source of elucidating information on this early period was presented and published by Kniisli at an American Chemical Society (ACS) Symposium in 1977. A part of this firsthand information is reported in extenso below. 

August 14 Geigy filed the basic patent Triazine Case No. 941 in Switzerland. (The US patent, NR. 2,891,855, was granted on June 23, 1959.) In this application, Geigy specifically described the herbicidal activity of chlorazine, simazine, and trietazine. In the same month, Dr. Gast reported that simazine and trietazine were fully tolerated by com at the rate of 10kg a.i./ha. Research emphasis was now on field trials for the remainder of the 1954 season, both in Switzerland and the United States. 

In the United States, approval of new herbicides depended not only on performance and toxicity data, but also on a clear picture of eventual crop and soil residues. The Geigy Analytical Department began immediately to develop a reliable residue method for simazine and other triazines. Working methods for residues in plants and soil were available by the end of 1956. 

By the end of the 1950s, atrazine was introduced for weed control on railroad tracks and rights-of-way and in com production in Europe. The initial federal approval in the United States occurred in December 1958 when the US Department of Agriculture (USDA) registered Geigy Atrazine 50W for use in com and for nonselective weed control in noncrop areas. In 1959 Atrazine 80 W was registered, which in 1970 was trademarked as AAtrex and quickly became a leading herbicide in the United States. 

The initial federal approval of an atrazine formulation in the United States occurred December 1, 1958, when the USDA registered Geigy Atrazine 50W for preemergence and postemergence control of several broadleaf weeds on corn and for nonselective weed control in noncrop areas. A wettable powder was the most popular choice for herbicide formulations at that time and could easily be sprayed uniformly across a field. 

Up to the late 1960s, only dry formulations of atrazine were available. Ciba-Geigy Corporation later developed the first water-based, flowable concentrate formulation of an herbicide, AAtrex 4L, which was approved on January 15, 1970. This development launched a new era in herbicide formulation technology. The water-based formulation improved the manufacturing process, minimized dust, was easier to package and to load into application equipment, and easier to mix. Gradually, more and more farmers who used atrazine switched to the liquid formulation, which is now the preferred formulation. 

Beginning in the 1950s, when triazines such as simazine, atrazine, prometryn, and ametryn were first synthesized and tested as selective herbicides in the Geigy laboratories in Basel, Switzerland (Gast et al 1955), massive research efforts have focused on the transformation and use of these compounds in the environment. The -triazines represent one of the most widely used and probably the most extensively studied family of herbicides. One of the driving forces for this research was the outstanding performance of triazines with respect to their selective herbicidal effects and crop tolerance. 

Ciba-Geigy. (1992). Reducing herbicide runoff role of best management practices. Technical Report 10-92. Submitted to USEPA. 

Several derivatives of moniliformin were synthesized and patented. Swiss patent 609,836 was awarded to Fischer and Bellus (Ciba Geigy) in 1979. The cyclobutene-3, 4-diones, R-alkyl, substituted Ph, CH2CH2SEt, CH2CH CH2, etc. are herbicides and PGR s. Thus postemergence application of 4Kg 1-octyloxycyclobutene-3, 4-dione/ha controlled Setaria italica, Lolium perenne, Sinapis alba and Stellaria media more than did the standard moniliformin Na salt" (Chem. Abstracts. Vol 90 1979, Indent 90 1988 82p). 

Atrazine was introduced by Geigy in 1958 (Fig. 3). It is a member of a large group of symmetrical tria-zine herbicides. Atrazine is a preemergence herbicide to which corn is tolerant. It is the number one herbicide in acreage treated and in dollars of sales in the United States. The compound is also used in orchards, pineapple, sorghum, and sugarcane. 

The triazines are very widely used herbicides. The best known and the most widely used of these compounds is atrazine. This compound ranks second in terms of usage in the United States (just behind glyphosate) 35-40 million kilograms of atrazine was used in 2001. This compound has been manufactured by Ciba-Geigy since... 

Some intermediates to fine chemicals are prepared industrially by vinylation of aromatics. We have selected three well-known products as representative cases, namely an intermediate to Naproxen, a non-steroidal antirheumatic drug (Albermarle) (Equation 11) an intermediate to Prosulfuron, a potent herbicide (Ciba Geigy-Novartis) (Equation 12) and a monomer for polymerization to Cyclotene electronic resins (Dow Chemicals) (Equation 13). 

Selman, F. (1996b). A Revised Assessment of Worker Exposure For Simazine in Response to the US Environmental Protection Agency Issuance of the Triazine Herbicides Position Document I Initiation of Special Review , Ciba-Geigy, ABR-96072, Submission by Ciba Crop Protection, Ciba-Geigy Corporation, Greensboro, NC, USA. 

SYNS AKTINIT S AQUAZINE BATAZINA 2,4-BIS(AETHYLAMINO)-6-CHLOR-l,3,5-TRIAZIN (GERMAN) BITEMOL BITEMOL S 50 CAT (herbicide) CDT CEKUSAN CEKUZINA-S CET l-CHLORO-3,5-BISETHYLAMINO-2,4,6-TRIAZINE 2-CHLORO-4,6-BIS(ETHYLAMINO)-s-TRIAZL E 2-CHLORO-4,6-BIS(ETHYLAMINO)-l,3,5-TRIAZINE FRAMED GEIGY 27,692 GESARAN GESATOP HERBAZIN HERBEX HERBOXY HUNGAZIN DT... 

---