Tolclofos-methyl Property

Melting point:

78-80°C

Boiling point:

338.5±52.0 °C(Predicted)

Density 

1.401±0.06 g/cm3(Predicted)

vapor pressure 

1.84 x 10^-3 (Pa 25 °C)

Flash point:

>100 °C

storage temp. 

2-8°C

solubility 

Chloroform (Slightly), DMSO (Slightly)

form 

Solid

Water Solubility 

1.10 mg l^-1 (25 °C)

color 

White to off-white

Merck 

13,9587

BRN 

2136521

InChIKey

OBZIQQJJIKNWNO-UHFFFAOYSA-N

LogP

4.560

CAS DataBase Reference

57018-04-9(CAS DataBase Reference)

NIST Chemistry Reference

Phosphorothioic acid, o-(2,6-dichloro-4-methylphenyl) o,o-dimethyl ester(57018-04-9)

EPA Substance Registry System

Tolclofos-methyl (57018-04-9)

Safety

Hazard Codes 

Xi,N

Risk Statements 

43-50/53

Safety Statements 

22-24/25-61-60-37-24

RIDADR 

UN 3077 9 / PGIII

WGK Germany 

3

RTECS 

TF0460000

HS Code 

29201900

Hazardous Substances Data

57018-04-9(Hazardous Substances Data)

Toxicity

LD50 in male, female rats, male, female mice (mg/kg): ~5000, ~5000, 3500, 3600 orally; all >5000 dermally; ~5000, 4900, 1070, 1260 i.p.; all >5000 s.c. (Ohtsuki, Fujinami)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H317May cause an allergic skin reaction

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P272Contaminated work clothing should not be allowed out of the workplace.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P333+P313IF SKIN irritation or rash occurs: Get medical advice/attention.

Tolclofos-methyl Chemical Properties,Usage,Production

Uses

Tolclofos-methyl is a non-systemic organophosphorus fungicide with both protective and curative activities that control soil-borne diseases caused by Rhizoctonia solani, Corticium rolfsii, Tphula incamata and Typhula ishikariensis in/on potatoes, sugar beet, cotton and peanuts.

Uses

Agricultural fungicide.

Definition

ChEBI: An organic thiophosphate that is 2,6-dichloro-4-methylphenol in which the hydrogen of the hydroxy group group has been replaced by a dimethoxyphosphorothioyl group. Tolclofos-methyl is a phospholipid biosynthesis inhibitor and fungicide that is used for co trolling soil-borne diseases caused by Typhula incarnata, Corticium rolfsii, Typhula ishikariensis, and Rhizoctonia solani.

Metabolic pathway

Tolclofos-methyl underwent common degradation and metabolic pathways in water, soil, plants and animals. These reactions are well documented for most organophosphorus compounds and include oxidative desulfuration, hydroxylation/oxidation of the 4-methyl group to the alcohol and carboxylic acid, cleavage of the P-O-aryl linkage, O-demethylation and conjugation. In addition to the above reactions, photolytic isomerisation to the thionate (P=S) was also observed. A schematic presentation of the primary metabolic pathways for tolclofosmethyl is illustrated in Scheme 1.

Degradation

[¹⁴C-phenyl]Tolclofos-methyl(1) was stable to hydrolytic degradation at pH 5, 7 and 9 at 22°C with DT₅₀ values of 139, 417 and 238 days, respectively. Higher temperature led to a more rapid hydrolysis and two hydrolysis products were detected. O-Demethylation and oxidative desulfuration were the major reactions to yield 2,6-dichloro-p-tolyl methyl hydrogen phosphorothioate (2) and toclofos-methyl oxon (O-2,6-dichlorop- tolyl O,O-dimethyl phosphate, 3), respectively. Cleavage of the P-O-aryl linkage yielded 2,6-dichloro-4-methylphenol(4) as a minor degradation product (WHO, 1994).
Tolclofos-methyl degraded in water under natural sunlight irradiation with DT₅₀ values of 44 days (in distilled water), 15-28 days (in natural river and pond water) and less than 2 days in 2% acetone/water. The major degradation reactions included oxidative desulfuration to yield compound 3 and O-demethylation to yield compound 2. The major photodegradation products in river and pond waters and soil thinlayer surfaces were compounds 2, 3, 4 and the O-demethylated 3 (2,6- dichloro-p-tolyl methyl hydrogen phosphate, 5) (Mikami et al., 1984). In acetone solution, demethylation of the isomerisation product [2,6- dichloro-p-tolyl O,S-dimethyl phosphorothioate (6)] yielded 2,6-dichlorop- tolyl S-methyl hydrogen phosphorothioate (7) and 2,6-dichloro-p-tolyl dihydrogen phosphate (8) as the major photodegradates (Mikami et al., 1984).

Toxicity evaluation

Its acute oral toxicity is very low in comparison with a thio-ester type of other organophosphorus fungicides (edifenphos, iprobenfos, and pyrazophos).