Fungicide

FRAC  3; DMI: imidazole

NOMENCLATURE

Common name prochloraz (BSI, E-ISO, (m) F-ISO, ANSI)

IUPAC name N-propyl-N-[2-(2,4,6-trichlorophenoxy)ethyl]imidazole-1-carboxamide; 1-{N-propyl-N-[2-(2,4,6-trichlorophenoxy)ethyl]}carbamoylimidazole 

Chemical Abstracts name N-propyl-N-[2-(2,4,6-trichlorophenoxy)ethyl]-1H-imidazole-1-carboxamide 

CAS RN [67747-09-5]  EEC no. 266-944-5  Development codes BTS 40 542 (Boots) 

PHYSICAL CHEMISTRY

Composition Tech. grade is c. 97% pure.  Mol. wt. 376.7  M.f. C15H16Cl3N3O2  Form Odourless, colourless crystals; (tech. is a mildly aromatic, golden brown liquid, that tends to solidify on cooling).  M.p. 46.5-49.3 ºC (>99% pure)  B.p. 208-210 ºC/0.2 mmHg (decomp.)  V.p. 1.5 ´ 10-1 mPa (25 ºC); 9.0 ´ 10-2 mPa (20 ºC)  KOW logP = 4.12 (unionised)  Henry 1.64 ´ 10-3 Pa m3 mol-1 (calc.)  S.g./density 1.42 (20 ºC)  Solubility In water 34.4 mg/l (25 ºC). Readily soluble in a wide range of organic solvents, e.g. chloroform, diethyl ether, toluene, xylene 2.5, acetone 3.5, hexane c. 7.5 ´ 10-3 (all in kg/l, 25 ºC).  Stability No degradation after 30 d (pH 5-7, 22 °C). Decomposes in concentrated acids and alkalis, in the presence of sunlight, and on prolonged heating at high temperatures (200 ºC).  pKa 3.8, weak base  F.p. 160 °C (closed cup) 

COMMERCIALISATION

History Fungicide reported by R. J. Birchmore et al. (Proc. Br. Crop. Prot. Conf. - Pests Dis., 1977, 2, 593). Introduced by The Boots Co., Ltd (now Aventis CropScience).  Patents GB 1469772; US 3991071; US 4080462  Manufacturers Aventis; Griffin

APPLICATIONS

Biochemistry Steroid demethylation (ergosterol biosynthesis) inhibitor.  Mode of action Fungicide with protective and eradicant action.  Uses A protectant and eradicant fungicide effective against a wide range of diseases affecting field crops, fruit, turf, and vegetables. An EC is recommended for use in cereals (400-600 g a.i./ha) against Pseudocercosporella, Pyrenophora, Rhynchosporium, and Septoria spp., with useful activity against Erysiphe spp.; in oilseed rape (500 g/ha) against Alternaria, Botrytis, Pyrenopeziza and Sclerotinia spp. Useful activity is also shown against Ascochyta and Botrytis spp. in field legumes; and Cercospora and Erysiphe spp. in beet. Good activity against storage or transit diseases of citrus and tropical fruit when applied as a dip treatment (0.5-0.7 g a.i./l). A WP is recommended in mushrooms against Verticillium fungicola and Mycogone perniciosa, and in rice against Pyricularia. A seed treatment (0.2-0.5 g/kg) will control several cereal diseases caused by Cochliobolus, Fusarium, Pyrenophora and Septoria spp., and, in flax, Alternaria.  Formulation types EC; EW; FS; LS; WP.  Compatibility Forms a complex with some metal ions, e.g. prochloraz-manganese used for WP formulations.  Selected tradenames: 'Sportak' (Aventis); 'Eyetak' (Barclay); 'Mirage' (Makhteshim-Agan); mixtures: 'Sponsor' (+ fenpropidin) (Aventis); 'Sportak Alpha' (+ carbendazim) (Aventis); 'Vista' (+ fluquinconazole) (Aventis)

OTHER TRADENAMES

'Abavit' (Aventis); 'Ascurit' (Aventis); 'Octave' (Aventis); 'Omega' (Aventis); 'Orbit' (Aventis); 'Prelude' (Aventis); 'Rival' (Aventis); 'Sporgon' (Aventis); 'Sprint' (Aventis); 'Alpha Mirage 40' (Makhteshim-Agan); 'Barclay Eyetak' (Barclay); 'Fungi' (Stefes); 'Master' (Vapco); 'Stefes Poraz' (Stefes) mixtures: 'Allure' (+ chlorothalonil) (Aventis); 'Evidan' (+ fluquinconazole) (Aventis); 'Foil' (+ fluquinconazole) (Aventis); 'Fongral' (+ bromuconazole) (Aventis); 'Nordika' (+ fenbuconazole) (Aventis); 'Novak' (+ carbendazim) (Aventis); 'Profile' (+ cyproconazole) (Aventis); 'Sportak Delta' (+ cyproconazole) (Aventis); 'Sportak Plus' (+ fluquinconazole) (Aventis); 'Sprint HF' (+ fenpropimorph) (Aventis); 'Stanza' (+ fenpropimorph) (Aventis); 'Tiptor' (+ cyproconazole) (Aventis); 'Agate' (+ tebuconazole) (spray, UK) (Bayer); 'Bonanza' (+ tetraconazole) (Sipcam Phyteurop); 'Bumper P' (+ propiconazole) (Makhteshim-Agan); 'Diams' (+ tebuconazole) (spray, France) (Bayer); 'Épopée' (+ tebuconazole) (spray, France) (Bayer); 'Mirage Extra' (+ fenbuconazole) (PBI, Makhteshim-Agan); 'Mirage Plus' (+ folpet) (Makhteshim-Agan); 'Mirage Super' (+ fenpropimorph) (Makhteshim-Agan); 'Nébraska' (+ tebuconazole) (spray, France) (Bayer)

ANALYSIS

Product analysis by hplc and glc. Residue analysis by glc. Details available from Aventis. 

MAMMALIAN TOXICOLOGY

Reviews FAO/WHO 40, 41 (see part 2 of the Bibliography).  Oral Acute oral LD50 for rats 1600-2400, mice 2400 mg/kg.  Skin and eye Acute percutaneous LD50 for rats >2100, rabbits >3000 mg/kg. Not irritating to skin; slight eye irritation (rabbits).  Inhalation LC50 (4 h) for rats >2.16 mg/l air.  NOEL (2 y) for dogs 30 mg/kg diet (0.92 mg/kg daily).  ADI (JMPR) 0.01 mg/kg b.w. [1983].  Toxicity class WHO (a.i.) III  EC hazard Xn; R22| N; R50, R53 

ECOTOXICOLOGY

Birds Acute oral LD50 for bobwhite quail 662, mallard ducks >1954 mg/kg. Dietary LC50 (5 d) for bobwhite quail and mallard ducks >5200 mg/kg.  Fish LC50 (96 h) for rainbow trout 1.5, bluegill sunfish 2.2 mg/l.  Daphnia LC50 (48 h) 4.3 mg/l.  Algae EbC50 (72 h) for Selenastrum capricornutum 0.1 mg/l; ErC50 1.54 mg/l.  Other aquatic spp. EC50 (96 h) for Eastern oyster (Crassostrea virginica) 0.95, mysid shrimp (Mysidopsis bahia) 0.77 mg/l.  Bees Low toxicity to bees. LD50 (topical) 50 mg/bee; (oral) 60 mg/bee.  Worms LC50 for earthworms (Eisenia foetida) 207 mg/kg soil.  Other beneficial spp. Low toxicity to a range of beneficial arthropods. 

ENVIRONMENTAL FATE