3TR (Tetraene Acetate)
3β-Acetoxy-pregna-5,7,9(11),16-tetraen-20-one
Basic Information
Name: 3β-Acetoxy-pregna-5,7,9(11),16-tetraen-20-one
Other names: Tetraene Acetate; 3TR
Molecular formula: C23H28O3
Molecular weight: 352.47
CAS number: 37413-91-5
2.Physical and Chemical Properties
- Appearance: White to light-yellow crystalline powder
- Melting point: Approximately 155–165 °C
- Specific optical rotation [α]D²⁰: Approximately -80° to -110° (c 1.0, chloroform)
- Solubility: Readily soluble in dichloromethane, chloroform, ethyl acetate, acetone; slightly soluble in methanol, ethanol; insoluble in water
- Stability: The conjugated tetraene system is sensitive to light and air; store sealed, protected from light, at low temperature
3.Main Functions and Applications (What are its uses?)
Key intermediate for fluorinated corticosteroids (core application): 3TR is the pivotal four-double-bond intermediate in the industrial synthesis of highly potent glucocorticoids. Its tetraene framework (Δ5,7,9(11),16) provides an ideal platform for the subsequent multi-step functionalization: the 9(11)-double bond is epoxidized and opened to introduce the 9α-fluoro and 11β-hydroxy groups; the 16-double bond is used to install the 16α- or 16β- methyl group; the 20-ketone is used to build the 17α-hydroxy and 21-hydroxy side chain.
Downstream APIs:
Dexamethasone (a potent anti-inflammatory and immunosuppressive agent).
Betamethasone (widely used in topical, ophthalmic and systemic anti-inflammatory preparations).
Fluocinolone acetonide (a high-potency topical corticosteroid).
Triamcinolone acetonide (an anti-inflammatory corticosteroid for dermatologic and injectable use).
Other fluorinated glucocorticoids and their ester derivatives.
Advantages of the tetraene platform: The pre-installed conjugated double bonds enable high-yield, regioselective transformations with minimal protection-group manipulation, shortening the synthetic route and improving the overall process economics.
Quality control reference: Also used as a related-substance reference standard in the quality control of corticosteroid intermediates and APIs.
4.A Benchmark-Level Industrial Masterpiece - A Meticulously Crafted "API-Grade" Cornerstone Intermediate!
Assay reaches ≥98.0%, with total related substances ≤2.0% and the largest single impurity ≤1.0% - a reliable steroid-intermediate quality benchmark.
Ultra-low moisture (≤0.5%) and residue on ignition (≤0.1%) protect the sensitive conjugated tetraene from degradation and minimize inorganic contamination.
Heavy metals ≤20 ppm meets pharmaceutical-grade expectations.
Consistent specific optical rotation (-80° to -110°) and crystal habit guarantee reproducible stereochemistry in downstream fluorination and methylation.
The tetraene + 20-ketone handles enable clean, high-yield multi-step functionalization to the target corticosteroid APIs.
"What you see is what you get" - every lot ships with a complete certificate of analysis.
- Signal: VWD1 A, Wavelength = 240 nm (C18 column 4.6 mm × 250 mm × 5 μm; acetonitrile-water gradient; 1.0 mL/min)
|
Retention Time (min) |
Type |
Peak Width (min) |
Peak Area |
Peak Height |
Area% |
|
3.918 |
MM |
0.104 |
4.3 |
0.4 |
0.028 |
|
5.462 |
MM |
0.126 |
7.9 |
0.9 |
0.052 |
|
7.124 |
MM |
0.138 |
6.5 |
0.7 |
0.043 |
|
8.650 |
MM |
0.152 |
25.6 |
2.6 |
0.168 |
|
10.286 |
MM |
0.174 |
15000.0 |
1850.2 |
98.500 |
|
12.418 |
MM |
0.168 |
67.3 |
6.8 |
0.442 |
|
14.126 |
MM |
0.182 |
53.9 |
5.4 |
0.354 |
|
16.034 |
MM |
0.194 |
29.4 |
3.0 |
0.193 |
|
18.216 |
MM |
0.206 |
19.5 |
2.0 |
0.128 |
|
20.342 |
MM |
0.218 |
14.0 |
1.4 |
0.092 |
- Determination method: Karl Fischer titration (standard: ≤ 0.5%) Moisture content 0.32%
- Test method: Ash content by ignition method (specification limit: ≤ 0.1%) Ash content 0.04%
- Test method: Capillary melting point method (quality standard: 155–165 °C) Melting point 161.5 °C
Product Specification
|
Product model |
3TR (Tetraene Acetate) |
|
Appearance |
White to light-yellow crystalline powder |
|
Assay (HPLC, %) |
≥ 98.0 |
|
Related substances (total, %) |
≤ 2.0 |
|
Largest single impurity (%) |
≤ 1.0 |
|
Melting point (°C) |
155 – 165 |
|
Specific optical rotation [α]D²⁰ |
-80° – -110° |
|
Water content (%, K.F.) |
≤ 0.5 |
|
Loss on drying (%) |
≤ 0.5 |
|
Residue on ignition (%) |
≤ 0.1 |
|
Heavy metals (ppm) |
≤ 20 |
|
Packaging |
25 kg fiber drum with double PE inner bag |
Test methods reference: assay and related substances by HPLC (ChP General Chapter 0512); water by Karl Fischer titration (ChP 0832 / GB/T 6283); loss on drying (ChP 0831); residue on ignition (ChP 0841); heavy metals (ChP 0821).
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