13423-73-9

Usage

Uses

Used in Pharmaceutical Industry:
3,5-Diisopropyl-4-hydroxybenzoic acid is used as an antioxidant for Propofol (P829750), a widely used intravenous anesthetic agent. Its antioxidant properties help prevent the oxidation of Propofol, thereby maintaining its stability and efficacy during storage and use.
Used in Chemical Synthesis:
3,5-Diisopropyl-4-hydroxybenzoic acid can be utilized as a key intermediate in the synthesis of various chemical compounds, particularly those with pharmaceutical or industrial applications. Its unique structure allows for further functionalization and modification to create novel molecules with specific properties and uses.
Used in Antioxidant Formulations:
Due to its antioxidant nature, 3,5-Diisopropyl-4-hydroxybenzoic acid can be employed in the development of antioxidant formulations for various industries, such as the food and cosmetics industries. It can help extend the shelf life of products and protect them from oxidative degradation, ensuring their quality and safety for consumers.

InChI:InChI=1/C13H18O3/c1-7(2)10-5-9(13(15)16)6-11(8(3)4)12(10)14/h5-8,14H,1-4H3,(H,15,16)

Synthetic route

isopropyl alcohol (67-63-0) + 4-hydroxy-benzoic acid (99-96-7) → 3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9)

Conditions	Yield
With sulfuric acid In water at 5 - 60℃; Large scale;	84%
at 40 - 60℃; Microwave irradiation;	78%
Stage #1: isopropyl alcohol; 4-hydroxy-benzoic acid With sulfuric acid In water at 15 - 65℃; for 4h; Friedel Crafts Alkylation; Stage #2: In water	74.6%

3,5-diisopropyl-4-hydroxybenzaldehyde (10537-86-7) → 3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9)

Conditions	Yield
With sodium chlorite; sodium dihydrogenphosphate; 2-methyl-but-2-ene In tetrahydrofuran; water; butan-1-ol at 20℃; for 16h;	68%

2,6-diisopropylphenol (2078-54-8) → 3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9)

Conditions	Yield
With hydrogenchloride; sodium methylate In N,N-dimethyl acetamide; water	23%
Multi-step reaction with 2 steps 1: acetic acid / water / 6 h / Reflux 2: sodium chlorite; sodium dihydrogenphosphate; 2-methyl-but-2-ene / water; tetrahydrofuran; butan-1-ol / 16 h / 20 °C View Scheme

carbon dioxide (124-38-9) + sodium-<2.6-diisopropyl-phenolate> → 3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9)

di-isopropyl ether (108-20-3) + 4-hydroxy-benzoic acid (99-96-7) → 3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9)

Conditions	Yield
With sulfuric acid at 10 - 65℃; Friedel-Crafts Alkylation;	120 g

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 2,6-diisopropylphenol (2078-54-8)

Conditions	Yield
Stage #1: 4-hydroxy-3,5-diisopropylbenzoic acid; sodium hydroxide In ethylene glycol at 140 - 145℃; for 7h; Inert atmosphere; Stage #2: With hydrogenchloride In water; ethylene glycol for 1h; pH=1 - 2;	93.5%
With decarboxylase at 25℃; for 15h; pH=6.5; Enzymatic reaction;	80.3%
With sodium hydroxide In 2-ethoxy-ethanol at 125 - 130℃; Large scale;	74%
Stage #1: 4-hydroxy-3,5-diisopropylbenzoic acid With sodium hydroxide In ethylene glycol at 140 - 145℃; Stage #2: With hydrogenchloride In water; ethylene glycol at 20℃; for 0.5h; pH=1 - 2;	53 g

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) + benzyl bromide (100-39-0) → benzyl 3,5-diisopropyl-4-hydroxybenzoate (160098-34-0)

Conditions	Yield
With potassium hydroxide In methanol; water; N,N-dimethyl-formamide; acetonitrile	79%

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) + hydroquinone (123-31-9) → C97H118O16

Conditions	Yield
Stage #1: 4-hydroxy-3,5-diisopropylbenzoic acid With toluene-4-sulfonic acid In para-xylene at 60℃; for 1.5h; Stage #2: hydroquinone In para-xylene at 110℃; for 16h;	61.5%

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) + allyl bromide (106-95-6) → 4-Allyloxy-3.5-diisopropyl-benzoesaeure (7192-38-3)

Conditions	Yield
With sodium methylate

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 4-Allyloxy-3.5-diisopropyl-benzoesaeure-aethylester (100347-71-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: NaOMe 2: (i) SOCl2, (ii) /BRN= 1718733/, Py View Scheme

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 4-Allyloxy-3.5-diisopropyl-benzonitril (102075-37-6)

Conditions	Yield
Multi-step reaction with 3 steps 1: NaOMe 2: (i) SOCl2, (ii) NH3 3: P2O5 / 165 °C View Scheme

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 4-Allyloxy-3.5-diisopropyl-benzamid (7192-63-4)

Conditions	Yield
Multi-step reaction with 2 steps 1: NaOMe 2: (i) SOCl2, (ii) NH3 View Scheme

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 3,3',5,5'-tetraisopropyl-[1,1'-biphenyl]-4,4'-diol (2416-95-7)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: sodium hydroxide / 2-ethoxy-ethanol / 125 - 130 °C / Large scale 2.1: iron(III) chloride / water / 1 h / 90 °C 2.2: 1 h / 20 °C View Scheme

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 2-(1-methylethoxy)-1,3-bis(1-methylethyl)benzene (141214-18-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: sodium hydroxide / 2-ethoxy-ethanol / 125 - 130 °C / Large scale 2: sodium hydroxide / N,N-dimethyl-formamide / 20 - 90 °C View Scheme

3,5-diisopropyl p-hydroxybenzoic acid (13423-73-9) → 2,6-diisopropyl-1,4-benzoquinone (1988-11-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: sodium hydroxide / 2-ethoxy-ethanol / 125 - 130 °C / Large scale 2: ammonium cerium (IV) nitrate / acetonitrile / 1 h / 20 - 80 °C View Scheme

Upstream product

• 124-38-9 carbon dioxide 
• 2078-54-8 2,6-diisopropylphenol 
• 10537-86-7 3,5-diisopropyl-4-hydroxybenzaldehyde 
• 99-76-3 methyl 4-hydroxylbenzoate 
• 67-63-0 isopropyl alcohol 
• 108-20-3 di-isopropyl ether 
• 99-96-7 4-hydroxy-benzoic acid 

Downstream Products

• 7192-38-3 4-Allyloxy-3.5-diisopropyl-benzoesaeure 
• 100347-71-5 4-Allyloxy-3.5-diisopropyl-benzoesaeure-aethylester 
• 102075-37-6 4-Allyloxy-3.5-diisopropyl-benzonitril 
• 7192-63-4 4-Allyloxy-3.5-diisopropyl-benzamid 
• 160098-34-0 benzyl 3,5-diisopropyl-4-hydroxybenzoate 
• 2078-54-8 2,6-diisopropylphenol 
• 1988-11-0 2,6-diisopropyl-1,4-benzoquinone 
• 141214-18-8 2-(1-methylethoxy)-1,3-bis(1-methylethyl)benzene 
• 2416-95-7 3,3',5,5'-tetraisopropyl-[1,1'-biphenyl]-4,4'-diol 

Relevant academic research and scientific papers

SIMPLE MANUFACTURING AND PURIFICATION TECHNOLOGY FOR HIGH PURITY PROPOFOL

A process for manufacturing Pure Propofol with a purity of more than 99.90% is disclosed, said process comprising dissolving Crude Propofol in a solvent in which it is soluble to form a solution, treating the solution with aqueous alkali to form an aqueous alkali layer and a solvent layer, separating the aqueous alkali layer from the solvent layer using a phase separation technique, distilling off the solvent from the solvent layer, and distilling a residue of the solvent containing Propofol using steam or boiling water in a presence of dilute alkali and antioxidant like metabisulfite, under normal pressure or mild vacuum.

Continuous flow synthesis of propofol

Herein, we report a continuous flow process for the synthesis of 2,6-diisopropylphenol— also known as Propofol—a short-acting intravenous anesthesia, widely used in intensive care medicine to provide sedation and hypnosis. The synthesis is based on a two-step procedure: a double Friedel–Crafts alkylation followed by a decarboxylation step, both under continuous flow.

PROCESS FOR THE PREPARATION OF PROPOFOL

The present provides a simple, convenient and time-efficient process for the preparation of propofol. Particularly, the present invention provides an improved process for the preparation of propofol using a heterocyclic base for the decarboxylation reaction. The present invention provides a time-efficient process for the preparation of propofol with high yield and purity.

Preparation method of propofol and structural analogues of propofol

The invention relates to a preparation method of propofol and structural analogues of propofol. The preparation method comprises the steps as follows: preparing an intermediate from p-hydroxybenzoic acid and alkyl alcohol as raw materials under the action of a solid acid catalyst, and then preparing a target product by a decarboxylase reaction. The preparation method has the characteristics of being green in synthesis, realizing biotransformation, causing little pollution, producing few by-products and the like, and is suitable for industrial production; the purity of the prepared products such as propofol is 99.6% or higher, which meets various medicinal standards.

PHARMACOLOGICALLY ACTIVE COMPOUNDS

The present invention relates to compounds of formula (I) shown below: wherein Q is as defined herein. The compounds of formula (I) act as selective positive allosteric modulators of strychnine-sensitive alpha 1-glycine receptors. The present invention further relates to the use of these compounds as therapeutic agents for the treatment and/or prevention of diseases or conditions in which strychnine-sensitive alpha 1-glycine receptor activity is implicated (such as, for example, chronic pain. The present invention also relates to processes for the preparation of these compounds and to pharmaceutical compositions comprising them.

Commercial manufacturing of propofol: Simplifying the isolation process and control on related substances

A commercially viable manufacturing process for propofol (1) is described. The process avoids acid-base neutralization events during isolation of intermediate, 2,6-di-isopropylbenzoic acid (3) and crude propofol, and thus simplifies the synthesis on industrial scale to a considerable extent. Syntheses of five impurities/related substances (USP and EP) are also described.

PHENOL C-ALKYLATION PROCESS

A method for obtaining high purity 2, 6-diisopropylphenol comprises alkylating 4- hydroxybenzoic acid in presence of an acid followed by basification and decarboxylating 4- hydroxy-3, 5-diisopropylbenzoic acid in presence of high boiling solvents and a catalyst at high temperature.

PROCESS FOR PREPARING EXTRA PURE 2, 6-DIISOPROPYL PHENOL

Disclosed herein is a process for the preparation of highly pure 2,6-diisopropyl phenol (Formula I), which comprises reacting p-hydroxy benzoic acid (Formula II) with an alkylating agent in presence of aq. mineral acid followed by basification and subsequent washings to yield 4-hydroxy-3,5-diisopropylbenzoic acid (Formula III) free of dimer impurity, 4, 4''-oxydibenzoic acid of Formula IV, ether impurity 3,5-di(propan-2-yl)-4- (propan-2-yloxy)benzoic acid of Formula V and the monoalkylated impurity 4-hydroxy- 3-(propan-2-yl) benzoic acid of Formula VI; and decarboxylating 4- hydroxy-3,5- diisopropylbenzoic acid (Formula III) in presence of high boiling solvent and sodium hydroxide as a catalyst at high temperature to yield 2, 6-diisopropyl phenol substantially free of ether impurity 1,3-di(propan-2-yl)-2-(propan-2-yloxy)benzene of Formula VII and monoalkylated phenol impurity 2-(propan-2-yl) phenol of Formula VIII. Propofol prepared by the process of the present invention is suitable for pharmaceutical use.

Long emission wavelength chemiluminescent compounds and their use in test assays

An assay method incorporating at least two different chemiluminescent compounds for detection and/or quantitation of at least two substances in a test sample is described. The synthesis of chemiluminescent reagents or conjugates for use in such methods as

Nickel salt-ester stabilizing compositions

Compositions of nickel salts of 4-hydroxybenzoic acids and esters of aliphatic or aromatic carboxylic acids, which esters have boiling points of at least about 250° C. are useful for stabilizing polyolefins against degradation by heat and ultraviolet radiation and for rendering polyolefins dyeable.