Common name:  Propiconazole

Iupac name: (±)-1-[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl]-1H-1, 2,4-triazole

Chemical abstracts name:   1[[2-(2,4-dichlorophenyl)-4-propy-l,3-dioxolan-2-yl]methyl] -1 H-1,2,4-triazole

Type: Fungicide

CAS RN: [60207 90-1] unstated stereochemistry

M.F.: C₁₅H₁₇Cl₂N₃O₂

Mol Wt: 342.2

 

Form (appearance): Yellowish, odourless, viscous liquid (tech.)

B.P.: 120℃(1.9 Pa);>250℃(101 kPa)

V.P.: 2.7×10^-2 mPa (20℃); 5.6×10^-2mPa(25℃)

S.G.: 1.29 (20℃)

Solubility.: In water 100 mg/l (20℃). In n-hexane 47 g/l. Completely miscible with ethanol, acetone, toluene and n octanol (25℃).

Stability: Stable up to 320℃; no significant hydrolysis

Henry: 9.2×10^-5 Pa m³ mol^-1 (20℃, calc.)

K_owlogP: 3.72 (pH 6.6,25℃)

Pka: 1.09, v. weak base

 

Formulation types: EC; SC; Emulsifiable gel.

Biochemistry: Steroid demethylation (ergosterol biosynthesis) inhibitor.

Mode of action: Systemic foliar fungicide with protective and curative action, with translocation acropetally in the xylem.

Uses: Systemic foliar fungicide with a broad range of activity, at 100-150 g/ha. On cereals, it controls diseases caused by Cochliobolus sativus, Erysiphe graminis, Leptosphaeria nodorum, Puccinia spp., Pyrenophora teres, Pyrenophora tritici repentis, Rhynchosporium secalis, and Septoria spp. In bananas, control of Mycosphaerella rnusicola and Mycosphaerella fijiensis var. difformis. Other uses are in turf against Sclerotinia homeocarpa, Rhizoctonia solani, Puccinia spp. and Erysiphe graminis; in rice against Rhizoctonia solani, Helminthosporium oryzae, and dirty panicle complex; in coffee against Hemileia vastatrix; in peanuts against Cercospora spp.; in stone fruit against Monilinio spp., Podosphaera spp., Sphaerotheca spp. and Tranzschelia spp.; in maize against Helminthosporium spp.

 

Oral: Acute oral LD₅₀ for rats 1517, mice 1490 mg/kg.

Skin and eye: Acute percutaneous LD₅₀ for rats >4000, rabbits >6000 mg/kg. Non-irritating to skin and eyes (rabbits). No sensitisation (guinea pigs).

Inhalation: LC₅₀ (4 h) for rats >5800 mg/m³.

Noel: (2 y) for rats 3.6, mice 10 mg/kg b.w. daily; (1 y) for dogs 1.9 mg/kg b.w. daily.

ADI: 0.02 mg/kg b.w.
Other Not mutagenic, not teratogenic. No carcinogenic potential of relevance for human exposure.

Toxicity: WHO (a.i.) II

EC hazard: (R22)

 

Birds: Acute oral LD₅₀ for Japanese quail 2223, bobwhite quail 2825, mallard ducks >2510, Pekin ducks >6000 mg/kg. LC₅₀ (8 d) for Japanese quail >1000, bobwhite quail >5620, mallard ducks >5620, Pekin ducks >1000 ppm.

Fish: LC₅₀ (96 h) for carp 6.8, rainbow trout 5.3, golden once 5.1, spot 2.6 mg/l. Daphnia EC₅₀ 4.8 mg/l.

Algae: EC₅₀ 0.02-13.6 mg/l for three freshwater algae and two diatom species.
Other aquatic spp. LC₅₀ (96 h) for crayfish 42 mg/l. EC₅₀ (96 h) for mysid shrimp (Mysidopsis bahia) 0.5 mg/l.

Worms: No toxic effects against Lumbricus rebellus.
Bees: Not toxic to bees; LD₅₀ (contact and oral) >100 pg/bee.
Other beneficial spp. Under field conditions, not expected to have any significant impact.

 

Plant: Degradation proceeds through hydroxylation of the n propyl side chain and deketalisation of the dioxolan ring. After cleavage of triazole, triazole-alanine is formed as the main metabolite. Metabolites are conjugated mostly as glucosides. For details of metabolites of propiconazole in wheat, rice and vines, see B. Donzel et al., IUPAC 7th Int. Congr. Pestic. Chem., 1990, 2, 160.

Animals: After oral administration to the rat, propiconazole is rapidly absorbed and also rapidly and almost completely eliminated with urine and faeces. Residues in tissues were generally Iow and there was no evidence for accumulation or retention of propiconazole or its metabolites. The major sites of enzymic attack are the propyl side-chain and the cleavage of the dioxolane ring, together with some attack at the 2,4 dichlorophenyl and 1,2,4-triazole rings. In the mouse, the major metabolic pathway is via cleavage of the dioxolane ring (R. Bissig & W. Muecke, Br. Crop Prot. Confi Pests Dis., 1988, 2, 675-680).

Soil/Environment: DT₅₀ in aerobic soils (25℃) 40-70 d. The main degradation pathways are hydroxylation of the propyl side-chain and the dioxolane ring, and finally formation of 1,2,4-triazole. K_{oc (ads)} 950 ml/g, immobile in soil.