2,2’-Bipyridine is a metalloprotease inhibitor used as a reagent for the colorimetric determination of iron. It is a base used for oxidation-reductions indicators and to confirm the presence of ferrous iron in soils. Additionally, 2,2’-bipyridine is used in transition metal catalysis and aluminum-initiated polymerization. It is a high-affinity iron chelator and may inhibit iron-containing enzymes.

2,3,4,6-Tetra-O-benzyl-D-glucopyranose is used for glucosylation reactions and as a reagent for synthesis of 1-C-alpha-D-glucopyranose derivatives.

2,3,4,6-Tetra-O-benzyl-D-mannopyranose is used for glucosylation reactions and as a reagent for synthesis of 1-C-alpha-D-glucopyranose derivatives.

Tetrazolium red is used to visualize dehydrogenase enzyme activity. Initially, the tetrazolium solution is colorless but changes to red when it comes into contact with hydrogen. Tetrazolium red is used in a biochemical viability test for seeds. The test relies on dehydrogenase enzymes to release hydrogen ions, which subsequently reduce the colorless tetrazolium salt solution to a red compound called formazan. Living cells turn red while dead cells remain colorless.

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has a variety of applications. DDQ is a deprotection agent for ketals, acetals, and thioacetals. It is a useful electron transfer reagent for synthesis of quinolones and an oxidizing agent used to synthesize steroids. Additionally, DDQ is used with Ph3P to synthesize 1,2-benzisoxazoles.

2,3-O-Isopropylidene-sn-glycerol is a reagent used in chemical synthesis. It is used in the preparation of tetraoxaspiroundecanes, diglycerides and glyceryl phosphates.

2,4,6-Tris(2-pyridyl)-1,3,5-triazine or TPTZ is a triazine compound containing 3 pyridyl groups. It is commonly used as a reagent for the spectrophotometric determination of Fe(II) and total Fe. It can also be used to determine the amount of acetaminophen in samples through spectrophotometry.

2,4-Dihydroxybenzoic acid is a resorcylic acid with a large number of applications. It possesses antioxidant, anti-radical and hydrogen peroxide scavenging. It also has potential as a wastewater treatment when activated with ultrasound. As a reagent it has been used to synthesize mycophenolic acid, protein 90 inhibitors and pde4 inhibitors.