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533610

Sigma-Aldrich

2-Acetyl-5-methylthiophene

98%

Synonym(s):

1-(5-Methyl-2-thienyl)ethanone, 1-(5-Methylthiophen-2-yl)ethan-1-one, 1-(5-Methylthiophen-2-yl)ethanone, 2-Methyl-5-acetylthiophene, 5-Methyl-2-thienyl methyl ketone, Methyl 5-methyl-2-thienyl ketone

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About This Item

Empirical Formula (Hill Notation):
C7H8OS
CAS Number:
Molecular Weight:
140.20
EC Number:
MDL number:
UNSPSC Code:
12352100
PubChem Substance ID:
NACRES:
NA.22

Quality Level

Assay

98%

refractive index

n20/D 1.561 (lit.)

bp

65-67 °C/1 mmHg (lit.)

mp

24-28 °C (lit.)

density

1.106 g/mL at 25 °C (lit.)

SMILES string

CC(=O)c1ccc(C)s1

InChI

1S/C7H8OS/c1-5-3-4-7(9-5)6(2)8/h3-4H,1-2H3

InChI key

YOSDTJYMDAEEAZ-UHFFFAOYSA-N

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.

Application

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

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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Palladium-catalysed direct 3-or 4-arylation of thiophene derivatives using aryl bromides.
Dong JJ, et al.
Tetrahedron, 50(23), 2778-2781 (2009)
Zinc azaphthalocyanines with thiophen-2-yl, 5-methylthiophen-2-yl and pyridin-3-yl peripheral substituents: Additive substituent contributions to singlet oxygen production.
M?rkved EH, et al.
Dyes and Pigments, 82(3), 276-285 (2009)
Novel Dithienylethenes with Extended ??Systems: Synthesis by Aldol Condensation and Photochromic Properties.
Altenhoner K, et al.
European Journal of Organic Chemistry, 2010(31), 6033-6037 (2010)
Experimental thermochemical study of the three methyl substituted 2-acetylthiophene isomers.
da Silva MAVR and Santos AFLOM.
The Journal of Chemical Thermodynamics, 40(8), 1309-1313 (2008)
Efficient guaiazulene and chamazulene syntheses involving [6+4] cycloadditions.
Mukherjee D, et al.
Journal of the American Chemical Society, 1010(1), 251-252 (1979)

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