3,4-Dihydro-2H-pyran Property

Melting point:

-70 °C (lit.)

Boiling point:

86 °C (lit.)

Density 

0.922 g/mL at 25 °C (lit.)

vapor density 

2.9 (vs air)

vapor pressure 

77.8 hPa (20 °C)

refractive index 

n20/D 1.440(lit.)

Flash point:

4 °F

storage temp. 

Store below +30°C.

solubility 

7.7g/l

form 

Liquid

color 

Clear colorless to yellow

PH

7 (5g/l, H2O, 20℃)

explosive limit

1.1-13.8%(V)

Water Solubility 

20 g/L (20 ºC)

BRN 

103493

Stability:

Volatile

InChIKey

BUDQDWGNQVEFAC-UHFFFAOYSA-N

LogP

0.690

CAS DataBase Reference

110-87-2(CAS DataBase Reference)

NIST Chemistry Reference

2H-Pyran, 3,4-dihydro-(110-87-2)

EPA Substance Registry System

2H-Pyran, 3,4-dihydro- (110-87-2)

Safety

Hazard Codes 

F,Xi

Risk Statements 

11-36/37/38-36/38-19

Safety Statements 

16-26-36-37/39-33-7/9

RIDADR 

UN 2376 3/PG 2

WGK Germany 

3

RTECS 

UP7700000

Autoignition Temperature

240 °C

Hazard Note 

Highly Flammable/Irritant

TSCA 

Yes

HazardClass 

3

PackingGroup 

II

HS Code 

29329995

Toxicity

LD50 orally in Rabbit: > 4000 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

H315Causes skin irritation

H317May cause an allergic skin reaction

H319Causes serious eye irritation

H412Harmful to aquatic life with long lasting effects

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P273Avoid release to the environment.

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

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

3,4-Dihydro-2H-pyran Chemical Properties,Usage,Production

Chemical Properties

colorless to light yellow liqui

Uses

Widely used hydroxyl-protecting reagent3,4-Dihydro-2H-pyran is used as a hydroxyl-protecting reagent in organic synthesis. It acts as an intermediate in synthetic chemistry. It is used to protect various reactive functional groups. It is involved in the polymerization reaction either alone or with unsaturated compound and finds application in polymer industries. Further, it is employed in the preparation of bicyclic compounds of epoxide-fused, halo compounds and allenic alcohols.

Flammability and Explosibility

Flammable

Safety Profile

A flammable and very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidzing materials. Keep away from heat and open flame. To fight fire, use alcohol foam, CO2, or dry chemical. When heated to decomposition it emits acrid smoke and irritating

Purification Methods

Partially dry dihydropyran with Na2CO3, then fractionally distil it. The fraction b 84-85o is refluxed with Na until hydrogen no longer evolves when fresh Na is added. It is then dried, and distilled again through a 60 x 1.2cm column packed with glass rings [Brandon et al. J Am Chem Soc 72 2120 1950, UV: Elington et al. J Chem Soc 2873 1952, NMR: Bushweller & O'Neil Tetrahedron Lett 4713 1969]. It has been characterised as the 3,5-dinitrobenzoyloxy-tetrahydrofuran derivative, m 103o which forms pale yellow crystals from dihydropyran/Et2O [Woods & Kramer J Am Chem Soc 69 2246 1947]. [Beilstein 17/1 V 181.]