4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE

Synonym(s):4-Phenyl-3,5-dihydro-4H-1,2,4-triazole-3,5-dione, PTAD;4-Phenyl-3H-1,2,4-triazole-3,5(4H)-dione;Cookson reagent;PTAD

CAS NO.：4233-33-4
Empirical Formula: C8H5N3O2
Molecular Weight: 175.14
MDL number: MFCD00003148
EINECS: 224-191-7
SAFETY DATA SHEET (SDS)
Update Date: 2024-08-15 19:00:21

4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE Structural

What is 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE?

Chemical properties

4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE is Red Solid

The Uses of 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE

4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE is used in the methods for determining levels of 1,25 dihydroxyvitamin d2 and d3 in biological and food samples and dietary supplements.

The Uses of 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE

4-Phenyl-1,2,4-triazoline-3,5-dione (PTAD) can be used as an efficient and selective reagent for the oxidation of thiols to disulfides.
It can also be used:???????

As a dehydrogenating agent to synthesize annulated dihydropyridazines by inverse [4+2] cycloaddition reaction between cyclic alkenes and 1,2,4,5-tetrazines.???????
As a dienophile to synthesize cycloaddition products by fast hetero-Diels?Alder reactions.???????
As an efficient oxidizing agent for the synthesis of pyridine derivatives from 1,4-dihydropyridines.
In the synthesis of urazoles via [3+2] cycloaddition with allylsilanes.

The Uses of 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE

4-Phenyl-1,2,4-triazoline-3,5-dione may be used as a derivatizing reagent for the determination of trace levels of 25-hydroxyvitamin D and its C-3 epimer in biological samples and cholecalciferol (vitamin D₃) in fortified infant formula, milk and milk powder using liquid chromatography–tandem mass spectrometry (LC–MS/MS)technique.

Synthesis Reference(s)

Synthetic Communications, 17, p. 409, 1987 DOI: 10.1080/00397918708063918

General Description

4-Phenyl-1,2,4-triazoline-3,5-dione, also known as Cookson reagent, is a strong dienophile, which gives a stable Diels-Alder adduct quantitatively within a short time and under mild conditions. It is commonly used as a protecting group of the diene moiety for the synthesis of vitamin D₃ (VD₃)-related compounds.

Purification Methods

PTAD forms carmine red needles by sublimation (ice cold finger) at 100o/0.1mm, and/or by recrystallisation from EtOH. IR: 1760 and 1780 cm-1 . [Cookson et al. Org Synth 51 121 1971, Moore max et al. J Org Chem 39 3700 1974, Beilstein 26 I 57, 26 III/IV 540.]

Properties of 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE

Melting point:	165-170 °C (dec.)(lit.)
Boiling point:	263.8±23.0 °C(Predicted)
Density	1.47±0.1 g/cm3(Predicted)
storage temp.	2-8°C
solubility	Chloroform (Sparingly), DMSO (Slightly), Ethyl Acetate (Slightly), Methanol (Sli
form	Solid
pka	-1.71±0.20(Predicted)
color	Red to Dark Red
BRN	141548
CAS DataBase Reference	4233-33-4(CAS DataBase Reference)

Safety information for 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE

Signal word	Warning
Pictogram(s)	Exclamation Mark Irritant GHS07
GHS Hazard Statements	H302:Acute toxicity,oral
Precautionary Statement Codes	P280:Wear protective gloves/protective clothing/eye protection/face protection. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.