Carbaryl

Names

IUPAC name

1-naphthyl methylcarbamate

Other names

Sevin
α-Naphthyl N-methylcarbamate

Identifiers

CAS Number

63-25-2^Y

3D model (Jmol)

CHEBI:3390^Y

ChEMBL46917^Y

5899^Y

200-555-0

D07613^Y

FC5950000

R890C8J3N1^Y

2757

InChI=1S/C12H11NO2/c1-13-12(14)15-11-8-4-6-9-5-2-3-7-10(9)11/h2-8H,1H3,(H,13,14)^Y

Key: CVXBEEMKQHEXEN-UHFFFAOYSA-N^Y
InChI=1/C12H11NO2/c1-13-12(14)15-11-8-4-6-9-5-2-3-7-10(9)11/h2-8H,1H3,(H,13,14)

Key: CVXBEEMKQHEXEN-UHFFFAOYAZ

SMILES

O=C(Oc2cccc1ccccc12)NC

Properties

Chemical formula

C₁₂H₁₁NO₂

Molar mass

201.23 g·mol⁻¹

Appearance

Colorless crystalline solid

Density

1.2 g/cm³

Melting point

142 °C (288 °F; 415 K)

Boiling point

decomposes

Solubility in water

very low (0.01% at 20°C)

Pharmacology

ATCvet code

QP53AE01 (WHO)

Hazards

Safety data sheet

ICSC 0121

EU classification (DSD)

Carc. Cat. 3
Harmful (Xn)
Dangerous for the environment (N)

R-phrases

R20/22 R40 R50

S-phrases

(S2) S22 S24 S36/37 S46 S61

Flash point

noncombustible

Lethal dose or concentration (LD, LC):

LD₅₀ (median dose)

710 mg/kg (rabbit, oral)
250 mg/kg (guinea pig, oral)
850 mg/kg (rat, oral)
759 mg/kg (dog, oral)
500 mg/kg (rat, oral)
150 mg/kg (cat, oral)
128 mg/kg (mouse, oral)
230 mg/kg (rat, oral)

US health exposure limits (NIOSH):

PEL (Permissible)

TWA 5 mg/m³

REL (Recommended)

TWA 5 mg/m³

IDLH (Immediate danger)

100 mg/m³

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

(what is ^YN ?)

Infobox references

Carbaryl (1-naphthyl methylcarbamate) is a chemical in the carbamate family used chiefly as an insecticide. It is a white crystalline solid commonly sold under the brand name Sevin, a trademark of the Bayer Company. Union Carbide discovered carbaryl and introduced it commercially in 1958. Bayer purchased Aventis CropScience in 2002, a company that included Union Carbide pesticide operations. It remains the third-most-used insecticide in the United States for home gardens, commercial agriculture, and forestry and rangeland protection. About 11 million kilograms were applied to U.S. farm crops in 1976. As a veterinary drug, it is known as carbaril (INN).

Carbaryl is produced by treating methyl isocyanate (3) with 1-naphthol (4).

Alternatively, 1-naphthol (1) is reacted with phosgene (2) to synthesize its chloroformate (3), which is then treated with methylamine to give the desired product (4):

The former process was carried out in Bhopal. In comparison, the latter synthesis uses exactly the same reagents, but in a different sequence. This synthesis avoids the preparation of methyl isocyanate, and the comparison is often used as a case study in green chemistry. However, the second synthesis still uses phosgene, which is toxic and reacts with water, and methylamine, which is a toxic and flammable gas.

Carbamate insecticides are slowly reversible inhibitors of the enzyme acetylcholinesterase. They resemble acetylcholine, but the carbamoylated enzyme undergoes the final hydrolysis step very slowly (minutes) compared with the acetylated enzyme generated by acetylcholine (microseconds). They interfere with the cholinergic nervous system and cause death because the effects of the neurotransmitter acetylcholine cannot be terminated by carbamoylated acetylcholinesterase.

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Wikipedia