24295-03-2

Basic information

• Product Name: 2-Acetylthiazole
• Synonyms: THIAZOLE-2-ACETYL;1-(1,3-Thiazol-2-yl)ethanone;1-(2-thiazolyl)-ethanon;2-Acetylthiazol;2-Thiazolylmethylketone;Acetylthiazole;Ketone, methyl 2-thiazolyl;1-(2-thiazolyl)-ethanone
• CAS NO: 24295-03-2
• Molecular Formula: C₅H₅NOS
• Molecular Weight: 127.16
• EINECS: 246-134-5
• Product Categories: ACETYLGROUP;Sulphur Derivatives;Thiazoles;thiazole Flavor;Building Blocks;Heterocyclic Building Blocks;A-B;Alphabetical Listings;Flavors and Fragrances
• Mol File: 24295-03-2.mol
• Article Data: 21

Chemical Properties

• Melting Point: 65.5°C
• Boiling Point: 89-91 °C12 mm Hg(lit.)
• Flash Point: 173 °F
• Appearance: White to slightly yellow/Powder or Crystals
• Density: 1.227 g/mL at 25 °C(lit.)
• Vapor Pressure: 0.173mmHg at 25°C
• Refractive Index: n20/D 1.548(lit.)
• Storage Temp.: Store below +30°C.
• PKA: 0.05±0.10(Predicted)
• Sensitive: Stench
• BRN: 109803
• CAS DataBase Reference: 2-Acetylthiazole(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Acetylthiazole(24295-03-2)
• EPA Substance Registry System: 2-Acetylthiazole(24295-03-2)

Safety Data

• Hazard Codes: Xn,Xi
• Statements: 22-36-43-36/37/38
• Safety Statements: 26-36/37-24/25-36
• RIDADR: 3334
• WGK Germany: 3
• F: 13
• TSCA: T
• HazardClass: STENCH
• Hazardous Substances Data: 24295-03-2(Hazardous Substances Data)

Usage

Chemical Properties

2-Acetylthiazole is a colorless to pale yellow liquid with green onion, herbal, grassy, hazelnuts, roasted meat, caramel, corn, and butter odor. Natural products are found in beef broth. Slightly soluble with water, soluble in most organic solvents. It is used in foods as antioxidant, as appearance control agent, and as flavoring ingredient.

Occurrence

2-Acetylthiazole is naturally found in raw asparagus, cooked asparagus, kohlrabi, cooked or boiled potatoes, turkey (roasted), raw chicken, boiled and cooked beef, grilled and roasted beef, pork liver, beer, Finnish whiskey, heated beans, other varieties of mushroom, rice bran, maize, and other natural sources.

Uses

2-Acetylthiazole can be used as a flavoring agent in food industries. It may be used as a food additive in the preparation of ′fragrant′ rice. It also was used in the preparation of triazolothiazoles, chiral alcohols and in aldol condensation reactions.

Preparation

2-Acetylthiazole is formed by oxidation of the corresponding carbinol using dichromate.

Aroma threshold values

Detection at 4 ppb

Taste threshold values

Taste characteristics at 30 ppm: corn chip with slightly musty background

Synthesis Reference(s)

The Journal of Organic Chemistry, 53, p. 1748, 1988 DOI: 10.1021/jo00243a029

General Description

2-Acetylthiazole is a volatile flavoring substance generally formed by the Maillard reaction between an amino acid and carbonyl compounds. It is reported to occur in canned sweet corn products, cooked pine mushroom, cooked asparagus and roasted beef.

Purification Methods

Check NMR spectrum; if it is not too bad, distil it through an efficient column in a vacuum. The oxime sublimes at 140-145o, m 159o, and when crystallised from H2O has m 163-165.5o. [Erlenmeyer et al. Helv Chim Acta 31 1142 1948, Waisvisz et al. J Am Chem Soc 79 4524 1957, Menasseé et al. Helv Chim Acta 40 554 1957, Beilstein 27 IV 2617.]

InChI:InChI=1/C5H5NOS/c1-4(7)5-6-2-3-8-5/h2-3H,1H3

Upstream product

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• 201230-82-2 carbon monoxide 
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Downstream Products

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• 166196-73-2 2-(1H-pyrazol-3-yl)-1,3-thiazole 
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• 1170699-69-0 (E)-4-methoxy-N-[1-(thiazol-2-yl)ethylidene]aniline 
• 1000029-34-4 1-(5-phenylthiazol-2-yl)ethanone 
• 135853-20-2 Methyl 3,4,6-Tri-O-benzyl-2-deoxy-1-(2-thiazolyl)-α-D-ribo-hexopyranoside 

Relevant articles and documents

Characteristic flavor formation of thermally processed N-(1-deoxy-α-D-ribulos-1-yl)-glycine: Decisive role of additional amino acids and promotional effect of glyoxal

The role of amino acids and α-dicarbonyls in the flavor formation of Amadori rearrangement product (ARP) during thermal processing was investigated. Comparisons of the volatile compounds and their concentrations when N-(1-deoxy-α-D-ribulos-1-yl)-glycine r

Synthetic method for 2-acetyl thiazole

The invention relates to a synthetic method for 2-acetyl thiazole. The synthetic method comprises the following steps: firstly, preparation of 2-amino thiazole is carried out, namely, toluene, thiourea and chloroacetaldehyde are mixed, a reaction is carried out with stirring at a constant temperature, and 2-amino thiazole is prepared; secondly, preparation of 2-bromo thiazole is carried out, namely, 2-amino thiazole is dissolved in sulfuric acid, cooling is carried out, a sodium nitrite aqueous solution is added drop by drop slowly at a controlled temperature after concentrated nitric acid is added drop by drop, stirring is carried out continuously, a reaction is carried out, the solution after the reaction is added in a mixed solution of sodium bromide and copper sulphate, a bromination reaction is carried out, and 2-bromo thiazole is prepared; thirdly, preparation of 2-acetyl thiazole is carried out, namely, 2-bromo thiazole is added in a butyllithium solution, stirring is carried out, then ethyl acetate is added, a reaction is carried out, and 2-acetyl thiazole is prepared. The acetylation step of 2-bromo thiazole is improved, the reaction raw material ratio and the reaction temperature are optimized, the high yield of the reaction is achieved, safe and reliable operation of the experiment is ensured effectively, and unexpected technical effects are achieved.

Aroma compounds generated from thermal reaction of l-ascorbic acid with l-cysteine

The reaction of l-ascorbic acid with l-cysteine in heated aqueous solution (141 ± 1 °C) at five different pH values (5.00, 6.00, 7.00, 8.00, or 9.00) for 2 h, resulted in the formation of a complex mixture of aroma volatiles. The volatile compounds generated were analysed by SPME-GC-MS. The results gave 43 aroma compounds. The reaction between l-ascorbic acid and l-cysteine led mainly to the formation of alicyclic sulphur compounds, thiophenes, thienothiophenes, thiophenones, thiazoles and pyrazines, most of which contain sulphur. Many of these volatiles had meaty flavour. The origin of many of the compounds was explained. The studies showed that thienothiophenes and thienones were formed mainly at acidic pH. In contrast, higher pH values could promote the production of thiophenes, thiazoles and pyrazines.