78-48-8

Basic information

• Product Name: 1,2,4-Tributylphosphorotrithioate
• Synonyms: 1-[bis(butylthio)phosphorylthio]butane;1-bis(butylsulfanyl)phosphorylsulfanylbutane;S,S,S-Tributyl phosphorotrithioate 250mg [78-48-8];Tribufos (DEF);Tribufos Solution, 100ppm;ANTI-DEF (N-TERM) antibody produced in rabbit;C1orf107;Digestive organ expansion factor homolog
• CAS NO: 78-48-8
• Molecular Formula: C₁₂H₂₇OPS₃
• Molecular Weight: 314.51
• EINECS: 201-120-8
• Product Categories: Method Specific;Oeko-Tex Standard 100;Pesticides;PesticidesPesticides&Metabolites;Plant growth regulatorsAlphabetic;TP - TZ
• Mol File: 78-48-8.mol
• Article Data: 5

Chemical Properties

• Melting Point: <-25°
• Boiling Point: bp0.3 150°; bp4 166.5°
• Flash Point: 200.4 °C
• Appearance: /
• Density: d204 1.0552
• Vapor Pressure: 1.73E-06mmHg at 25°C
• Refractive Index: nD20 1.534
• Storage Temp.: 0-6°C
• CAS DataBase Reference: 1,2,4-Tributylphosphorotrithioate(CAS DataBase Reference)
• NIST Chemistry Reference: 1,2,4-Tributylphosphorotrithioate(78-48-8)
• EPA Substance Registry System: 1,2,4-Tributylphosphorotrithioate(78-48-8)

Safety Data

• Hazard Codes: T,N
• Statements: 24/25-50/53
• Safety Statements: 36/37-45-61-60
• RIDADR: UN 2811
• RTECS: TG5425000
• HazardClass: 6.1(a)
• PackingGroup: II
• Hazardous Substances Data: 78-48-8(Hazardous Substances Data)

Usage

Description

DEF is a cholinesterase-inhibiting organophosphorus pesticide compound used as a cotton defoliant that was registered in 1960.DEF is a colorless to pale-yellow transparent liquid with a skunk-like odor.It is completely miscible with n-hexane, dichloromethane, toluene, and 2-propanol and has an octanol–water partition coefficient of 3.31×105 at 25°C. DEF toxicity is primarily attributed to inhibition of various esterases, including acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), neuropathic target esterase (NTE), and carboxylesterase, resulting in increased accumulation of endogenous acetylcholine (ACh) in cholinergic nerve terminals and related effector organs.

Chemical Properties

Tribufos is a colorless to yellow liquid. Tribufos is relatively stable to acids and heat and is hydrolyzed slowly under alkaline conditions. Tribufos has a mercaptan or skunk-like odor. Tribufos has a mercaptan or skunk-like odor. Practically insoluble in water (2.3×10-4 g/ 100 mL); completely miscible in dichloromethane, n-hexane, 2-propanol, toluene.

Uses

Different sources of media describe the Uses of 78-48-8 differently. You can refer to the following data:
1. DEF is an organophosphate chemical used as a cotton defoliant to facilitate mechanical harvesting. Recommended application rate is ～1–2.5 pints per acre per year applied as a diluted spray. Two products containing DEF as their active ingredient include DEF 6, manufactured by Bayer Corporation, and Folex 6 DC, manufactured by Amvac Chemical Co. Used for pest control in industrial agriculture (tends to be more toxic agents), organophosphates of low to intermediate toxicity are used to control ectoparasites on farm and companion animals and humans (head lice), and for home and garden pest control.
2. Defoliant.
3. 1,2,4-Tributylphosphorotrithioate is a defoliant for cotton.

General Description

Colorless to pale yellow liquid with mercaptan-like odor. Insoluble in water; soluble in aliphatic, aromatic, and chlorinated hydrocarbons.. Used as a growth regulator.

Air & Water Reactions

Insoluble in water. Hydrolyzed slowly by alkaline conditions.

Agricultural Uses

Different sources of media describe the Agricultural Uses of 78-48-8 differently. You can refer to the following data:
1. Herbicide, Defoliant, Plant growth regulator: Tribufos is an organophosphate defoliant used for cotton crops. It is specifically used to defoliate cotton in preparation for machine harvesting. It was first registered in the United States in 1961. Not approved for use in EU countries . Registered for use in the U.S.
2. Defoliants are substances that induce premature shedding of leaves and facilitate harvesting. Defoliants and desiccants are both harvesting aids, and are used as herbicides, as many are toxic in nature. They may be organic or inorganic. Tribufos is a very effective defoliant for cotton and one of the many harvesting aids in use, for various kinds of crops.

Trade name

B-1776?; BUTIFOS?; BUTIPHOS?[C]; CHEMAGRO? 1776; CHEMAGRO? B-1776; DE- GREEN?; DEF?; DEF DEFOLIANT?; DELEAFDEFOLIANT?; EASY OFF?-D; E-Z-OFF? D; FOLEX? 6EC FOS-FALL? A; ORTHO? phosphate defoliant

Safety Profile

A poison by ingestion, skin contact, and intraperitoneal routes. Experimental reproductive effects. Animal experiments show an anti-cholinesterase effect. When heated to decomposition it emits toxic fumes of PO, and SO,. See also PARATHION, PHOSPHATES, ESTERS, and SULFATES.

Carcinogenicity

No carcinogenic effects occurred when rats were given diets with 0, 4, 40, or 320 ppm tribufos (equivalent to 0.0, 0.2, 1.8, and 16.8 mg/kg/day in males and 0.0, 0.2, 2.3, and 21.1 mg/kg/day in females, respectively) for 2 years . In a carcinogenicity study, mice were fed diets containing tribufos at doses of 0, 10, 50, or 250 ppm (equivalent to 0.0, 1.64, 8.28, or 48.02 mg/kg/day in males and 0.0, 2.08, 11.14, or 63.4 mg/kg/day in females) for 90 weeks . Carcinogenic effects were evident at 250 ppm (48.02 mg/kg/day in males and 63.4 mg/kg/day in females). Males exhibited a statistically significant increase in hemangiosarcomas and adenocarcinomas of the small intestines and females exhibited a statistically significant increase in alveolar/bronchiolar adenomas.

Environmental Fate

Soil. Hydrolyzes in soil to ethyl mercaptan, carbon dioxide and diisobutylamine (Hartley and Kidd, 1987). Butylate is probably subject to degradation of soil microorganisms. It was reported that butylate may degrade via hydrolysis of the ester linkage forming the corresponding mercaptan (ethyl mercaptan), alkylamine (diisobutylamine) and carbon dioxide. Transthiolation and oxidation of the mercaptan forms the alcohol which may further oxidize to afford a metabolic pool (Kaufman, 1967). Somasundaram and Coats (1991) reported butylate in soils is oxidized to the corresponding sulfoxide. The reported half-life in soil is approximately 1.5–10 weeks (Worthing and Hance, 1991). The reported half-life of butylate in a loam soil at 21–27°C was 3 weeks (Humburg et al., 1989). Residual activity in soil is limited to approximately 4 months (Hartley and Kidd, 1987). Groundwater. According to the U.S. EPA (1986) butylate has a high potential to leach to groundwater. Plant. In plants, butylate is metabolized to carbon dioxide, diisobutylamine, fatty acids, conjugates of amines and other compounds (Hartley and Kidd, 1987; Humburg et al., 1989).

Toxicity evaluation

DEF is relatively stable in aqueous solutions (pH 5 and 7) up to 32 days but slightly degraded at pH 9 with a half-life of 124 days. The hydrolytic breakdown product of DEF is known as desbutylthio tribufos. DEF is stable up to 30 days in sandy loam soil exposed to natural sunlight, but degrades in aqueous solution upon exposure to natural sunlight for 30 days, with an estimated half-life of 44 days. The estimated soil adsorption coefficient (Kd) for DEF ranges from 60.6 for sandy loam soil to 106 for clay loam. The estimated soil adsorption constant (Koc) for DEF ranges from 4870 for silt loam to 12 684 for sand. DEF is highly persistent in soil with biodegradation half-lives of 745 and 389 days in sandy loam soil under aerobic and anaerobic conditions. Based on water solubility, high soil adsorption, hydrolysis, and aerobic soil metabolism data, DEF is not identified as a potential groundwater contaminant. However, DEF is likely to become airborne following aerial application or ground spraying. Also, while DEF itself is not significantly volatile, its degradation product, n-butyl mercaptan (nBM), is volatile and accounts for a skunk-like odor near areas where DEF has been applied. DEF is also formed via release of the defoliant merphos, which undergoes rapid oxidation under environmental conditions to tribufos. DEF has a vapor pressure of 5.3×10-6 mm Hg at 25°C, suggesting its occurrence in both vapor and particulate phases in ambient atmosphere. Vaporphase DEF degrades by interacting with photochemically produced hydroxyl radicals; half-life for this reaction in air is estimated to be 5 h. Particulate-phase DEF gets removed from atmosphere by wet and dry deposition. Volatilization of DEF from water surfaces is not an important fate process based on its Henry’s Law constant of 2.9  107 atmm3 mol1 at 20°C.

InChI:InChI=1/C12H27OPS3/c1-4-7-10-15-14(13,16-11-8-5-2)17-12-9-6-3/h4-12H2,1-3H3

Synthetic route

1-butanethiol (109-79-5) → S,S,S-tributylphosphorotrithioate (78-48-8)

Conditions	Yield
Stage #1: n-butanethiol With phosphorus; potassium hydroxide In dimethyl sulfoxide; toluene at 20℃; for 7h; Schlenk technique; Stage #2: With dihydrogen peroxide In dimethyl sulfoxide; toluene at 20℃; for 0.5h; Schlenk technique;	83%
(i) phosphorus, nBuSNa, CCl4, (ii) aq. H2O2, AcOH; Multistep reaction;

S,S,S-tributylphosphorotrithioate (78-48-8) + toluene-4-sulfonic acid (104-15-4) → 4-Methylbenzolthiosulfonsaeure-S-butylester (28519-31-5)

Conditions	Yield
In benzene for 15h; Heating;	21%

S,S,S-tributylphosphorotrithioate (78-48-8) → 1-butanethiol (109-79-5)

Conditions	Yield
With methanol; 5,5'-dithiobis-(2-nitrobenzoic acid); Sphingobium sp. TCM1 phosphotriesterase; manganese(ll) chloride In aq. buffer at 30℃; pH=8; Kinetics; Enzymatic reaction;

Upstream product

• 109-79-5 n-butanethiol 
• 150-50-5 merphos 

Downstream Products

• 28519-31-5 4-Methylbenzolthiosulfonsaeure-S-butylester 
• 109-79-5 n-butanethiol 

Relevant articles and documents

Diphenyl Diselenide-Catalyzed Synthesis of Triaryl Phosphites and Triaryl Phosphates from White Phosphorus

Industrially important triaryl phosphites, traditionally prepared from PCl3, have been synthesized by a diphenyl diselenide-catalyzed one-step procedure involving white phosphorus and phenols, which provides a halogen- and transition metal-free way to these compounds. Subsequent oxidation of triaryl phosphites produces triaryl phosphates and triaryl thiophosphates. Phosphorotrithioates are also prepared efficiently from aromatic thiols and aliphatic thiols.

Direct synthesis of phosphorotrithioites and phosphorotrithioates from white phosphorus and thiols

White phosphorus (P4) is still the major commercial P-atom source for the production of organophosphorus compounds. Conventionally, C-S-P bonds were constructed from environmentally questionable P(O)X directly or indirectly. From the green chemistry point of view, formation of C-S-P bonds from inorganic molecule P4 in an easy-to-operate and atom-economical way is essential because it will avoid the hazardous chlorination process. Only five methods for the formation of C-S-P bonds from P4 have been developed over the past 70 years. Here, the first general and high-yielding synthesis of P(SR)3 and P(O)(SR)3 involving P4 and thiols is presented. With the use of KOH or K2CO3 as a base and DMSO-toluene as a solvent, both arythiols and alkylthiols are tolerant in this transformation. The reaction is characterized by a complete conversion of white phosphorus. This operationally simple and environmentally sound reaction shows a broad scope of substrates and good functional group tolerance. Moreover, this method can be easily adapted to large-scale preparation.

Pesticide compositions and method

Toxicant, especially pesticide compositions, having lowered dermal toxicity are provided. The compositions include a lipophilic-pesticide, a nonionic surfactant and a dry inert diluent carrier. Methods for reducing the dermal toxicity of lipophilic toxicants, especially pesticides are provided, as well as methods for controlling insect pests using the disclosed compositions.