The Freshdicator Diagnostic kit designed for on-site seafood/meat spoilage detection, will offer distinct competitive advantages in analysis time, cost per test, ease of reagent storage and convenient on-site testing capability.

The Freshdicator Wafer/Wrap, an on-package seafood/meat/poultry freshness sensor for the real time monitoring of product freshness.

Si-HOBt (Catalog # H 1002) is 1-hydroxybenzotriazole-6-carboxamidopropyl silica gel for the formation of immobilized activated ester and sulfonate ester reagents for the facile formation of amides and sulfonamides, respectively. Si-HOBt is also utilized for the protection of amines as carbamates via immobilized carbonate esters. Currently available in bulk format (5g and 25g sizes) Aurora is pleased to announce the availability of pre-loaded SPE tubes (250 mg and 500 mg Si-HOBt per tube).

Si-HOBt is activated utilizing standard coupling chemistry followed by reaction with amines to generate high yields of pure product after filtration. Si-HOBt is quite suitable for parallel and combinatorial synthesis applications. The used Si-HOBt is readily regenerated and can be recycled for further use.

References:

Dendrinos, K. et al (1998) Chem Comm, 499.
Dendrinos, K., Kalivretenos, A.G. (1998) J. Chem Soc Perkin Trans I, 1463.
Dendrinos, K., Kalivretenos, A.G. (1998) Tetrahedron Lett, 39, 1321.
Kalivretenos, A.G. US Patent # 7,229,835.
Vokkaliga, S. et al (2011) Tetrahedron Lett., 52, 2722.

Why Silica Based HOBt reagents?

Si-HOBt offers distinct advantages over polystyrene reagents and other silica gel bound acylating agents:

1. Recyclable: Used Si-HOBt is readily regenerated for further use.
2. Solvent Independent: Silica works with a wide variety of solvents, including aqueous mixtures without shrinking or swelling.
3. Ease of Use: Silica can be agitated by shaking, overhead stirring and even using magnetic stirrers for up to four hours.
4. Reproducibility and Scalability: Silica based reactions perform the same on small and large-scale. What works in the lab will work in production.

Applications in Education

Solid Phase Organic Chemistry (SPOC) has become commonplace in synthetic chemistry and provides distinct advantages over solution phase chemistry in combinatorial chemistry and high-throughput synthesis. Unfortunately SPOC techniques are not found in current Organic Laboratory curriculum.

The use of Si-HOBt in the Organic Laboratory class is the ideal way of introducing SPOC to future organic chemists. Due to its ease of use and ability to be recycled, Si-HOBt updates the Organic Chemistry Lab class in an effective and economical way. Straightforward experiments designed around amide and sulfonamide formation are readily incorporated into the curriculum.

In collaboration with Dr. Paul Smith of the University of Maryland Baltimore County (UMBC) Aurora has developed a two week Organic Laboratory experiment for benzamide synthesis utilizing solution phase synthesis and modern SPOC (utilizing Si-HOBt in SPE tube format).*

*manuscript submitted to J. Chem. Ed.

Si-HOBt and Beyond

Aurora now offers pre-activated Si-HOBt-OR resins (Cat # A 1001 Si-HOBt-OAc and Cat # B 1001 Si-HOBt-OBz). Si-HOBt-OAc and Si-HOBt-OBz react with amines to form acetamides and benzamides, respectively. Applications include the preparation of amide libraries as well as amine derivatization for GC and HPLC analysis.

The following Si-HOBt products are in final pre-commercialization development:

Si-HOBt-OTs is pre-activated as a tosyl ester for the direct reaction with amines to form N-tosylated derivatives.

Currently Available Products from AthenaES®
Cat # 0901 – E 1001: Ethyl β-D-glucuronide
Cat # 0901D – E 1002: Ethyl β-D-glucuronide-d5
Cat # 0903 – P 1001: Propyl β-D-glucuronide
Cat # 0902 – E 1006: Ethyl sulfate, sodium salt
Cat # 0902D – E 1007: Ethyl sulfate-d5, sodium salt