Oligonucleotide synthesis reagents

5-Benzylthio-1H-tetrazole (BTT)

CAS21871-47-6

5-Benzylthio-1H-tetrazole (BTT, CAS 21871-47-6) is a tetrazole-based activator for the coupling step of phosphoramidite oligonucleotide synthesis. BTT is more acidic than both 1H-tetrazole and ETT, which shortens coupling times for 2′-O-TBDMS and TOM-protected RNA phosphoramidites. King-Pharm supplies BTT for research and manufacturing, with a batch-specific certificate of analysis.

Chemical structure of 5-Benzylthio-1H-tetrazole (BTT)
C8H8N4S · 192.24 g/mol
CAS No.
21871-47-6
Formula
C8H8N4S
Mol. weight
192.24 g/mol
Appearance
White to Off-white Powder

Product Description

5-Benzylthio-1H-tetrazole, commonly known as BTT (also called BMT, 5-benzylmercaptotetrazole), is a tetrazole-based activator used in phosphoramidite chemistry for oligonucleotide synthesis, particularly RNA synthesis.

During the coupling step, BTT protonates the diisopropylamino group of a nucleoside phosphoramidite and forms a reactive tetrazolide intermediate, which then couples with the free 5′-hydroxyl group of the growing oligonucleotide chain.

BTT is more acidic than ETT and 1H-tetrazole (pKa about 4.1, against about 4.3 and 4.9). With 2′-O-TBDMS RNA phosphoramidites, coupling with BTT takes about 3 minutes, while 1H-tetrazole needs 12 minutes or more. BTT also dissolves in acetonitrile up to about 0.44 M, which is higher than 1H-tetrazole.

When evaluating BTT for a process, buyers usually check the assay, the water content, the clarity of a 0.25 M solution in anhydrous acetonitrile, packaging integrity and batch-to-batch consistency.

Chemical Specifications

Identifiers

CAS number 21871-47-6
Product name 5-Benzylthio-1H-tetrazole (BTT)
IUPAC name 5-benzylsulfanyl-2H-tetrazole
Synonyms 5-Benzylthio-1H-tetrazole; 5-Benzylmercapto-1H-Tetrazole; 5-Benzylmercaptotetrazole; 5-[(Phenylmethyl)Thio]-1H-Tetrazole; 5-[(Phenylmethyl)Thio-1H-Tetrazole; BMT; BTT; 5-(Benzylthio)-1H-Tetrazoel; 5-((Phenylmethyl)Thio)-1H-Tetrazole
Molecular formula C8H8N4S
Molecular weight 192.24 g/mol
MDL number MFCD00068731
PubChem CID 323185
InChIKey GXGKKIPUFAHZIZ-UHFFFAOYSA-N
SMILES C1=CC=C(C=C1)CSC2=NNN=N2

Physical and chemical properties

Appearance White to Off-white Powder
Melting Point 133.0-138.0 ( ℃ )

Applications

BTT is used at the coupling step of solid-phase oligonucleotide synthesis, usually as a 0.25 M solution in anhydrous acetonitrile.

RNA synthesis

BTT activates 2′-O-TBDMS and 2′-O-TOM protected RNA phosphoramidites with shorter coupling times than 1H-tetrazole.

DNA synthesis

BTT can also serve as a general activator for DNA phosphoramidites on automated synthesizers.

Modified oligonucleotides

Its higher acidity suits sterically hindered or modified phosphoramidites that couple slowly with 1H-tetrazole.

Activator solution preparation

Solid BTT lets users prepare activator solutions in-house at the concentration their process requires.

Quality Documentation

The following documents can be provided for 5-Benzylthio-1H-tetrazole (BTT) to support technical evaluation and purchasing. Documents are issued for the specific grade and batch supplied.

  • Certificate of Analysis (COA) Batch-specific test results against the specification.
Request batch COA

Packaging, Storage & Transport

Storage Temp Store at room temperature in a dry, well-ventilated place. Keep container tightly closed. ( ℃ )

Packaging can be adapted to the order quantity and destination.

Frequently Asked Questions

How does BTT compare with ETT and 1H-tetrazole?

BTT is the most acidic of the three (pKa about 4.1, against about 4.3 for ETT and 4.9 for 1H-tetrazole). For 2′-O-TBDMS RNA monomers, coupling with BTT takes about 3 minutes, compared with 12 minutes or more with 1H-tetrazole.

At what concentration is BTT usually used?

BTT is usually used as a 0.25 M solution in anhydrous acetonitrile. Keep the solvent dry, because water lowers coupling efficiency.

How should BTT be stored?

Keep BTT tightly sealed in a cool, dry place, protected from moisture and preferably under an inert atmosphere. Follow the storage conditions on the label and SDS.

What is the CAS number of 5-Benzylthio-1H-tetrazole (BTT)?

The CAS Registry Number of 5-Benzylthio-1H-tetrazole (BTT) is 21871-47-6. 5-Benzylthio-1H-tetrazole (BTT) is also known as 5-Benzylthio-1H-tetrazole; 5-Benzylmercapto-1H-Tetrazole; 5-Benzylmercaptotetrazole.

What is the molecular formula and molecular weight of 5-Benzylthio-1H-tetrazole (BTT)?

The molecular formula of 5-Benzylthio-1H-tetrazole (BTT) is C8H8N4S, and its molecular weight is 192.24 g/mol.

What is 5-Benzylthio-1H-tetrazole (BTT) used for?

BTT is used at the coupling step of solid-phase oligonucleotide synthesis, usually as a 0.25 M solution in anhydrous acetonitrile.

Which quality documents are available for 5-Benzylthio-1H-tetrazole (BTT)?

The following documents are available for 5-Benzylthio-1H-tetrazole (BTT): Certificate of Analysis (COA). Contact King-Pharm to request the documents for a specific batch.

How can I request a quotation for 5-Benzylthio-1H-tetrazole (BTT)?

Send an inquiry for 5-Benzylthio-1H-tetrazole (BTT) (CAS 21871-47-6) with the required quantity, target specification, destination country and any documentation requirements. King-Pharm will confirm availability, packaging, lead time and price.

Request a Quote for 5-Benzylthio-1H-tetrazole (BTT)

Tell us the required quantity, target specification, destination country and any documentation requirements. We will confirm availability, packaging, lead time and price.

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Page last reviewed on by Leo Xiao.