NOMENCLATURE

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

IUPAC name (RS)-2-(2,4-dichlorophenyl)-1-(1H-1,2,4-triazol-1-yl)hexan-2-ol 

Chemical Abstracts name (?-a-butyl-a-(2,4-dichlorophenyl)-1H-1,2,4-triazole-1-ethanol 

CAS RN [79983-71-4]  Development codes PP523; ICIA0523 (both ICI) 

PHYSICAL CHEMISTRY

Composition Tech. is >85% pure.  Mol. wt. 314.2  M.f. C₁₄H₁₇Cl₂N₃O  Form White, crystalline solid.  M.p. 110-112 ºC  V.p. 0.018 mPa (20 ºC)  K_OW logP = 3.9 (20 ºC)  Henry 3.33 ´ 10^-4 Pa m³ mol^-1 (calc.)  S.g./density 1.29 g/cm³ (25 ºC)  Solubility In water 0.017 g/l (20 ºC). In dichloromethane 336, methanol 246, acetone 164, ethyl acetate 120, toluene 59, hexane 0.8 (all in g/l, 20 ºC).  Stability Stable for at least 6 years at ambient temperatures. Stable to hydrolysis and photolysis in water. Formulations stable in sales containers for 6 months at 50 ºC, and 2 years at ambient temperature. 

APPLICATIONS

Biochemistry Inhibits ergosterol biosynthesis (steroid demethylation inhibitor).  Mode of action Systemic fungicide with protective and curative action.  Uses Control of many fungi, particularly Ascomycetes and Basidiomycetes, e.g. Podosphaera leucotricha and Venturia inaequalis on apples, Guignardia bidwellii and Uncinula necator on vines, Hemileia vastatrix on coffee, and Cercospora spp. on peanuts, at 15-250 g/ha. Also used on bananas, cucurbits, peppers and other crops.  Phytotoxicity Non-phytotoxic when used as directed. Some injury noted on McIntosh apples.  Formulation types OL; SC; SG. 

ANALYSIS

Product by gc and FID. Residues by gc with either NPD, thermionic or ECD detection. See K. J. Harradine et al., in Comp. Anal. Profiles, Chapt. 2.

MAMMALIAN TOXICOLOGY

Reviews FAO/WHO 59, 61 (see part 2 of the Bibliography).  Oral Acute oral LD₅₀ for male rats 2189, female rats 6071 mg/kg.  Skin and eye Acute percutaneous LD₅₀ for rats >2000 mg/kg. Mild irritant to eyes; non-irritating to skin (rabbits). Moderate skin sensitiser (guinea pigs).  Inhalation LC₅₀ (4 h) for rats >5.9 mg/l.  NOEL (90 d) for rats 5, rabbits 50 mg/kg daily.  ADI (JMPR) 0.005 mg/kg b.w. [1990].  Other Non-mutagenic.  Toxicity class WHO (a.i.) III (Table 5); EPA (formulation) IV  EC hazard Xi; R43| N; R51, R53 

ECOTOXICOLOGY

Birds Acute oral LD₅₀ for mallard ducks >4000 mg/kg.  Fish LC₅₀ (96 h) for rainbow trout 3.4, mirror carp 5.94, sheepshead minnow 5.4 mg/l.  Daphnia LC₅₀ (48 h) 2.9 mg/l.  Bees Acute oral and contact LD₅₀ for honeybees >0.1 mg/bee.  Worms LC₅₀ (14 d) 414 mg/kg. 

ENVIRONMENTAL FATE

Animals Readily excreted by mammals, with no significant retention in organs or tissues.  Plants For details of the metabolism of hexaconazole in cereals, see M. W. Skidmore et al., Br. Crop Prot. Conf. - Pests Dis., 1990, 3, 1035-1040.  Soil/Environment Rapidly degraded in soils in laboratory tests.