Dimethyl phosphite Property

Boiling point:

170-171 °C(lit.)

Density 

1.2 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.402(lit.)

Flash point:

71 °C

solubility 

Chloroform (Slightly), Methanol (Slightly)

form 

Colorless liquid with a mild odor

Water Solubility 

Soluble in water.

Sensitive 

Moisture Sensitive

BRN 

1697490

Stability:

Stable. Moisture sensitive. Incompatible with water, strong oxidizing agents, acid chlorides, strong bases.

InChI

InChI=1S/C2H7O3P/c1-4-6(3)5-2/h6H,1-2H3

InChIKey

HZCDANOFLILNSA-UHFFFAOYSA-N

SMILES

P(=O)(OC)OC

CAS DataBase Reference

868-85-9(CAS DataBase Reference)

NIST Chemistry Reference

Phosphonic acid, dimethyl ester(868-85-9)

IARC

3 (Vol. 48, 71) 1999

EPA Substance Registry System

Dimethyl phosphite (868-85-9)

Safety

Hazard Codes 

Xn

Risk Statements 

21-36-10-68-52/53-43-40

Safety Statements 

26-36/37-61

RIDADR 

UN 3278 6.1/PG 3

WGK Germany 

1

RTECS 

SZ7710000

TSCA 

Yes

HazardClass 

3.2

PackingGroup 

III

HS Code 

29209013

Hazardous Substances Data

868-85-9(Hazardous Substances Data)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H317May cause an allergic skin reaction

H341Suspected of causing genetic defects

H351Suspected of causing cancer

H412Harmful to aquatic life with long lasting effects

Precautionary statements

P201Obtain special instructions before use.

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.

P308+P313IF exposed or concerned: Get medical advice/attention.

Dimethyl phosphite Chemical Properties,Usage,Production

Chemical Properties

colourless liquid

Uses

As a flame retardant on Nylon 6 fibers; intermediate in the production of pesticides and herbicides; as a stabilizer in oil and plaster; an additive to lubricants

Uses

1. Dimethyl Phosphite（DMP）is used as a reagent in the synthesis of 4-(thiophen-2-ylmethyl)-2H-phthalazin-1-ones as potent PARP-1 inhibitors.
2. It is also used as a reagent in the synthesis of estafiatin phosphonate derivatives which exhibit antibacterial and antifungal activity.
3. Dimethyl Phosphite is a degradation product of the pesticides trichlorphon and malathion and may be released into the envionment following their application. It is a contaminant (approxiately 2%) in the chemical intermediate triethyl phosphite, which hydrolyses readily to dimethyl hydrogen phosphite in the presence of moist air or water.
4. Dimethyl Phosphite is used as a flame retardant on Nylon 6 fibres and, in combination with guanidine and formaldehyde, to impart flame and crease resistance to cotton textiles. The compound is also used to increase fire resistance to cellulosic textiles, acrolein-grafted polyamide fibres and y-irdiated polyethylene.
5. lt is used as a lubricant additive, as a chemical intermediate in the production of organophosphorous pesticides and as an adhesive.
6. Dimethyl Phosphite has also been used as a stabilizer in oil and plaster and, in combination with pyroctechol, as a corrosion inhibitor on steel.

Definition

ChEBI: Dimethyl hydrogen phosphite is an organooxygen compound.

Application

DMP is a basic chemical which is used industrially as an intermediate. Because of its reactivity
DMP participates in a large number of chemical reactions:

• Addition to oxo compounds
• Addition to oxo compounds with subsequent condensation e.g. with amines
• Oxidation with oxygen or chlorine
• Addition to alkenes

• water treatment chemicals e.g. corrosion inhibitors for cooling-water circuits (about 50 %)
• pesticides and pharmaceuticals (about 20 %)
• flame retardants and other specialities (about 15 %)
• textile finishing products (about 15 %)

Synthesis Reference(s)

Canadian Journal of Chemistry, 34, p. 1819, 1956 DOI: 10.1139/v56-235

Health Hazard

Dimethyl Phosphite (DMP) is rapidly absorbed via the oral and dermal routes. The main metabolic pathway in rodents is demethylation to monomethyl hydrogen phosphite (MMP) and further oxidation to CO2. DMP was mainly eliminated via urine and expired air. Over the studied dose range between 10 and 200 mg/kg bw and 5 x 200 mg/kg bw, respectively, only little evidence of bioaccumulation or saturation of absorption and elimination was observed. The only difference in studied toxicokinetics between rats and mice was the more rapid metabolism and elimination in mice.
An inhalation LC50 value is not available, but an exposure of 7100 mg/m³ (concentration estimated based on air flow and net loss of material) over 6 hours was not lethal for rats, mice and guinea pigs. Clinical signs were observed in mice only, and included occasionally laboured respiration after approximately 2 hours of exposure and ptosis after 5 hours. The acute dermal LD50 was 681 mg/kg bw (rabbits). Signs of intoxication were depression, ptosis, labored respiration, ataxia and placidity. The acute oral LD50 values were: 3283 mg/kg bw for male rats, 3040 mg/kg bw for female rats, 2815 mg/kg bw for male mice, and between 2150 and 3160 mg/kg bw for female mice. Clinical signs were inactivity, weakness, prostration and shallow breathing at doses near to or exceeding the LD50 values. White opaque eyes were seen in male mice.
Dimethyl Phosphite is irritating to the skin and eyes of rabbits. After prolonged or repeated exposures moderate to severe irritation of skin and mucosa was observed in rats. No sensitisation studies are available.

Proposed metabolic pathways of DMP in rats and mice (Nomeir and Matthews, 1997).

Safety Profile

Suspected carcinogen with experimental carcinogenic data. Moderately toxic by ingestion and skin contact. A skin and eye irritant. Mutation data reported. When heated to decomposition it emits toxic fumes of POx

Carcinogenicity

Dimethyl hydrogen phosphite was not mutagenic to several strains of Salmonella typhimurium, but it did cause sister chromatid exchanges and chromosomal aberrations in the Chinese hamster CHO line.
An ACGIH threshold limit value (TLV) has not been established for dimethyl hydrogen phosphite.