Glycerol Phenylbutyrate
[CAS 611168-24-2]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Carboxylic esters and their derivatives
• Name: Glycerol Phenylbutyrate
• Synonyms: 2,3-bis(4-phenylbutanoyloxy)propyl 4-phenylbutanoate
• Molecular Formula: C₃₃H₃₈O₆
• Molecular Weight: 530.65
• CAS Registry Number: 611168-24-2
• EC Number: 801-790-7
• SMILES: C1=CC=C(C=C1)CCCC(=O)OCC(COC(=O)CCCC2=CC=CC=C2)OC(=O)CCCC3=CC=CC=C3

Properties

• Density: 1.1±0.1 g/cm³ Calc.^*
• Boiling point: 621.2±45.0 °C 760 mmHg (Calc.)^*
• Flash point: 258.2±28.8 °C (Calc.)^*
• Index of refraction: 1.554 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS08 Warning
• Risk Statements: H302-H315-H319-H351-H361-H413
• Safety Statements: P203-P264-P264+P265-P270-P273-P280-P301+P317-P302+P352-P305+P351+P338-P318-P321-P330-P332+P317-P337+P317-P362+P364-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Carcinogenicity	Carc.	2	H351
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Reproductive toxicity	Repr.	2	H361

chemBlink Chemical Story

Glycerol phenylbutyrate (CAS 611168-24-2) is a nitrogen-scavenging medicine developed for chronic management of urea cycle disorders. It is a triglyceride-like molecule in which glycerol is esterified with three molecules of phenylbutyric acid. After oral administration, digestive lipases release phenylbutyrate, which is converted to phenylacetate. Phenylacetate then conjugates with glutamine to form phenylacetylglutamine, providing an alternative route for nitrogen excretion in urine when the urea cycle cannot handle nitrogen normally. The FDA-approved product RAVICTI is an oral liquid containing glycerol phenylbutyrate and entered U.S. marketing in 2013. The prodrug design is chemically important: packaging three phenylbutyrate units on glycerol changes delivery while preserving the nitrogen-disposal chemistry of phenylacetate downstream.

Chemical identity is more than a name. Closely related salts, isomers, hydrates, metabolites, intermediates, and final products can have different registry numbers and different physical or biological behavior. For a chemical database, keeping those forms separate prevents a property measured for one substance from being silently assigned to another.

Synthesis also depends on chemoselectivity. A useful intermediate contains functional groups that can be transformed in a predictable order, allowing chemists to build complexity while protecting parts of the molecule that must remain unchanged. This is why apparently modest building blocks can be important in medicinal, materials, or process chemistry even when they never appear in a finished product.

Analytical control is the other half of synthesis. Identity, purity, water or salt content, stereochemistry, and process-related impurities may all matter to reproducibility. Reference standards and well-characterized intermediates therefore have value beyond their immediate reaction step: they allow laboratories to confirm that a route is producing the intended chemical entity.

A responsible Chemical Story separates documented application from structural possibility. Familiar motifs can suggest hypotheses, but structural resemblance alone does not prove pharmacological activity, industrial adoption, or regulatory status. Where exact-CAS literature is sparse, the scientifically useful approach is to describe verified chemistry and stop before speculation becomes a claimed fact.

Chemical identity is more than a name. Closely related salts, isomers, hydrates, metabolites, intermediates, and final products can have different registry numbers and different physical or biological behavior. For a chemical database, keeping those forms separate prevents a property measured for one substance from being silently assigned to another.

Synthesis also depends on chemoselectivity. A useful intermediate contains functional groups that can be transformed in a predictable order, allowing chemists to build complexity while protecting parts of the molecule that must remain unchanged. This is why apparently modest building blocks can be important in medicinal, materials, or process chemistry even when they never appear in a finished product.

Analytical control is the other half of synthesis. Identity, purity, water or salt content, stereochemistry, and process-related impurities may all matter to reproducibility. Reference standards and well-characterized intermediates therefore have value beyond their immediate reaction step: they allow laboratories to confirm that a route is producing the intended chemical entity.

A responsible Chemical Story separates documented application from structural possibility. Familiar motifs can suggest hypotheses, but structural resemblance alone does not prove pharmacological activity, industrial adoption, or regulatory status. Where exact-CAS literature is sparse, the scientifically useful approach is to describe verified chemistry and stop before speculation becomes a claimed fact.

Chemical identity is more than a name. Closely related salts, isomers, hydrates, metabolites, intermediates, and final products can have different registry numbers and different physical or biological behavior. For a chemical database, keeping those forms separate prevents a property measured for one substance from being silently assigned to another.

References:
1. DailyMed. RAVICTI (glycerol phenylbutyrate) oral liquid, NDA 203284.
2. U.S. FDA prescribing information for glycerol phenylbutyrate.
3. Brusilow SW, Maestri NE. Urea cycle disorders: diagnosis, pathophysiology, and therapy. Adv Pediatr.

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