1-(5-Methyl-2-thienyl)ethan-1-one Chemical Properties

Melting point:

24-28 °C(lit.)

Boiling point:

65-67 °C1 mm Hg(lit.)

Density 

1.106 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.561(lit.)

FEMA 

4643 | 2-ACETYL-5-METHYLTHIOPHENE

Flash point:

>230 °F

storage temp. 

under inert gas (nitrogen or Argon) at 2–8 °C

form 

Low Melting Crystalline Mass, Powder or Crystals

Specific Gravity

1.119

color 

White to pale yellow

Odor

at 1.00 % in propylene glycol. sweet spicy honey hawthorn almond acacia hyacinth caramellic graham cracker

Odor Type

spicy

Sensitive 

Light Sensitive

JECFA Number

2107

BRN 

110854

LogP

2.04

CAS DataBase Reference

13679-74-8(CAS DataBase Reference)

NIST Chemistry Reference

2-Acetyl-5-methylthiophene(13679-74-8)

Safety Information

Hazard Codes 

Xn,Xi

Risk Statements 

20/21/22

Safety Statements 

36/37-22

RIDADR 

UN 3335

WGK Germany 

3

RTECS 

OB4972000

Hazard Note 

Irritant

HazardClass 

STENCH

HS Code 

29349990

MSDS

• Language:English Provider:1-(5-Methyl-2-thienyl)ethan-1-one
• Language:English Provider:ACROS
• Language:English Provider:SigmaAldrich
• Language:English Provider:ALFA

1-(5-Methyl-2-thienyl)ethan-1-one Usage And Synthesis

Chemical Properties

white to light yellow crystal powder

Uses

2-Acetyl-5-methylthiophene may be used in the preparation of:

• 2-ethyl-5-methylthiophene
• (5-methylthiophen-2-yl)glyoxal
• (2E)-1-(5-methylthiophen-2-yl)-3-(pyridin-3-yl)prop-2-en-1-one
• ethyl 3-(5-methylthiophen-2-yl)-3-oxopropanoate

Definition

ChEBI: 2-acetyl-5-methylthiophene is a thiophene that is substituted by acetyl and methyl groups at positions 2 and 5, respectively. It has a role as a flavouring agent. It is an aromatic ketone, a member of thiophenes and a methyl ketone.

General Description

2-Acetyl-5-methylthiophene is a volatile organic compound formed during the reaction between L-cysteine and dihydroxyacetone in glycerine or triglyceride solvent system. It can be prepared by reacting 2-methylthiophene with acetic anhydride. 2-Acetyl-5-methylthiophene undergoes palladium-catalyzed cross-coupling reaction with aryl bromides to form C-4 arylated product. It reacts with 1,2-bis(5-formyl-2-methylthiophen-3-yl)cyclopentene via Aldol condensation to form a chalcone with photochromic property. The standard molar enthalpies of combustion, formation and vaporization of 2-acetyl-5-methylthiophene are 4341.9 ± 1.8kJ/mol, 158.0 ± 2.1kJ/mol and 62.0 ± 2.6kJ/mol, respectively.

Safety Profile

A poison by intraperitoneal route. A flammable liquid. When heated to decomposition it emits toxic vapors of SOx.

1-(5-Methyl-2-thienyl)ethan-1-one(13679-74-8)Related Product Information

• 1-(5-Methyl-2-thienyl)ethan-1-one
• 2-Methyl-5-propionylthiophene
• 2-ACETYL-3-AMINO-5-PHENYLTHIOPHENE
• 2-ACETYL-5-CYANOTHIOPHENE
• 5-Acetylthiophene-2-carboxylic acid
• 1-(3-methyl-2-thienyl)ethan-1-on
• 1-(4-methyl-2-thienyl)ethan-1-one
• 2-Acetylthiophene
• 1-[3-AMINO-5-(4-CHLOROPHENYL)-2-THIENYL]ETHAN-1-ONE
• 2-ACETYL-3-AMINO-5-T-BUTYLTHIOPHENE
• 1-{5-[3-(DIMETHYLAMINO)PROP-1-YNYL]-2-THIENYL}ETHAN-1-ONE
• 1-(5-ETHYL-THIOPHEN-2-YL)-ETHANONE
• 3-(2-ACETYL-5-TERT-BUTYL-THIOPHEN-3-YLCARBAMOYL)-ACRYLIC ACID
• N-(2-ACETYL-5-TERT-BUTYL-THIOPHEN-3-YL)-SUCCINAMIC ACID
• 1-(3,5-DIMETHYL-2-THIENYL)ETHAN-1-ONE
• 2-[5-(2-CHLOROACETYL)-2-THIENYL]ACETIC ACID
• N1-(2-ACETYL-5-PHENYLTHIEN-3-YL)-2-CHLOROACETAMIDE
• N1-[2-ACETYL-5-(TERT-BUTYL)-3-THIENYL]-2,3,3-TRICHLOROACRYLAMIDE