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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.)

functional group

ketone

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

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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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