Thiazolyl Blue is an organic compound with a chemical formula of C16H14ClN5S and a molecular weight of 353.84 g/mol. It is also known as MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide). Dark blue solid. Soluble in water, methanol, ethanol and dimethyl sulfoxide, insoluble in non-polar solvents such as n-heptane. It decomposes when exposed to light, so it should be kept in a dark, dry place.
Thiazolyl Blue is a tetrazole compound with some special chemical properties. The following are the chemical properties of Thiazolyl Blue:
1. Redox reactions can occur: Thiazolyl Blue can be converted into other compounds under different redox conditions. For example, it can be reduced by enzymes in the mitochondrial respiratory chain as acceptors by acting as a substrate with NADH to produce a water-soluble purple product.
2. Prone to catalyst action: Thiazolyl Blue can be used as a catalyst for copper ions to catalyze various reactions such as the oxidation of ferrous oxide and aldehyde compounds.
3. Can form complexes with metal ions: Sulfur, nitrogen and other atoms in Thiazolyl Blue can form complexes with metal ions, such as copper complexes, thus affecting its absorption and fluorescence properties.
4. It can be decolorized under strong alkaline conditions: Thiazolyl Blue will decolorize under strong alkaline conditions and produce a colorless product.
To sum up, the chemical properties of Thiazolyl Blue are complex and diverse, and these properties play an important role in its application fields.
The synthetic routes of Thiazolyl Blue mainly include the following types:
1. Griess-Reagent route:
The Griess-Reagent route is one of the earliest synthetic methods of Thiazolyl Blue, and its synthetic route includes the following steps:
(1) react phenylsulfonyl chloride and 1,2-ethylenediamine to obtain N,N'-diphenylsulfonyl-1,2-ethylenediamine;
(2) React N,N'-diphenylsulfonyl-1,2-ethylenediamine and nitroaniline under alkaline conditions to generate 2,3-dimethyl-5-nitro-4-phenyl Thiazoline (TNBT);
(3) Reduction of TNBT to 2,3-dimethyl-5-methoxycarbonyl-4-phenylthiazoline (MTT).
Among them, Griess-Reagent is a mixture used as a reducing agent in the reaction process, and its composition includes sodium nitrite and sulfuric acid. The function of Griess-Reagent is to reduce nitrobenzoic acid to nitrobenzophenone and promote the formation of MTT intermediate. During the reaction process, Griess-Reagent also plays a role in adjusting the pH value to maintain the appropriate pH of the reaction.
It should be noted that the reaction conditions in the Griess-Reagent route need to be carefully controlled, and parameters such as reaction temperature, pH value and reaction time will affect the effect of the reaction and the purity of the product. In addition, since Griess-Reagent contains toxic substances such as sodium nitrite, strict safety regulations must be followed during operation.
2. WST-1 route:
The WST-1 route is one of the improved synthetic methods of Thiazolyl Blue, which mainly includes the following steps:
(1) react benzaldehyde and thiourea under alkaline conditions to obtain N-benzylthiourea (BSMT);
(2) React BSMT and nitrobenzene under basic conditions to generate 2-(4-methoxycarbonylphenyl)-4,5-dimethylthiazoline (WST-1).
3. MTS route:
The MTS route is another improved synthetic method of Thiazolyl Blue, and its synthetic route includes the following steps:
(1) React thiourea and benzaldehyde under alkaline conditions to generate N-benzylthiourea (BSMT);
(2) React BSMT and aniline under alkaline conditions to generate MTS.
4. MTT route:
The MTT route is one of the simplest synthetic methods for Thiazolyl Blue, which mainly includes the following steps:
(1) React nitrobenzene and 1,2-ethylenediamine under alkaline conditions to generate 2,3-dimethyl-5-nitro-4-phenylthiazoline (TNBT);
(2) Reduction of TNBT to 2,3-dimethyl-5-methoxycarbonyl-4-phenylthiazoline (MTT).
To sum up, the synthesis routes of Thiazolyl Blue are quite diverse, among which the Griess-Reagent route and WST-1 route are more commonly used synthetic methods, while the MTS route and MTT route are relatively simple.