79-31-2 Usage
Chemical Properties
Isobutyric acid is a clear colorless oily liquid with an odor and flavor similar to n-butyric acid. Miscible with water, soluble in ethanol and ether. Prepared via oxidation of isobutyl alcohol.
Physical properties
Isobutyric Acid is a flavoring agent that is a colorless liquid with a strong, penetrating odor, resembling butter. it is miscible in alcohol, propylene glycol, glycerin, mineral oil, and most fixed oils and soluble in water. it is obtained by chemical synthesis. it is also termed isopropylformic acid.
Occurrence
Isobutyric acid occurs naturally in Ceratonia siliqua L. The gum obtained from the kernels of this species is used as a thickener in the food industry. Reported found in several essential oils: Arnica montana, Roman chamomile, Laurus nobilis, imperatoria, and in carob fruits (Siliqua dulcis); also identified in the essence of Seseli tortuosum, Artemisia transiliensis.
Uses
Isobutyric acid is used to prepare esters for flavors and perfumes. It is also used as a disinfecting agent, preservative and tanning agent. It finds applications in textile, varnish and the leather industry. Further, it is used as a lactation stimulant in dairy cattle. In addition to this, it is used in the preparation of tetramethylsuccinic acid and diisopropyl ketone.
Preparation
Isobutyric acid is prepared in a similar way to butyric acid, mainly by direct oxidation of isobutanol and isobutyraldehyde, which is obtained by a direct oxidation reaction with air or oxygen.
Application
Isobutyric acid is mainly used in the synthesis of isobutyric acid esters, such as methyl isobutyrate, propyl ester, isoamyl ester and benzyl ester. It can also be used manufacture of esters for solvents, flavors and perfume bases, disinfecting agent, varnish, plasticizers, deliming hides, tanning agent and used in pharmaceutical. Isobutyric acid has some important derivatives that, in the industry, is actually used for the production of isobutyronitrile intermediates, and then converted to isobutylamidine hydrochloride that is the raw materials of pesticide diazinon.
Definition
ChEBI: Isobutyric acid is a branched fatty acid comprising propanoic acid carrying a methyl branch at C-2. It has a role as a volatile oil component, a plant metabolite and a Daphnia magna metabolite. It is a branched-chain saturated fatty acid, a methyl-branched fatty acid and a fatty acid 4:0. It is a conjugate acid of an isobutyrate.
Aroma threshold values
Detection: 10 ppb to 9.5 ppm; aroma characteristics at 10 ppm: acidic pungent, dairy buttery and cheesy
with fruity undertones.
Taste threshold values
Taste characteristics at 15 ppm: acidic, sour dairy, creamy, cheese, cultured dairy nuance.
General Description
Isobutyric acid appears as a colorless liquid with a light odor of rancid butter. Flash point 132°F. Density 7.9 lb / gal. Corrosive to metals and tissue.
Air & Water Reactions
Flammable. Water soluble
Reactivity Profile
Isobutyric acid corrodes aluminum and other metals. Flammable hydrogen gas may accumulate in enclosed spaces in which this reaction has taken place [USCG, 1999].
Health Hazard
Inhalation causes irritation of nose and throat. Ingestion causes irritation of mouth and stomach. Contact with eyes or skin causes irritation.
Fire Hazard
Flammable/combustible material. May be ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Biochem/physiol Actions
Odor at 10 ppm
Synthesis
The preparation of isobutyric acid is similar with butyric acid, which is performed by the direct oxidation of isobutyl alcohol and isobutyraldehyde. Isobutyric acid can be directly generated from the oxidation of isobutyraldehyde in air or oxygen. Other manufacturing methods have isobutyronitrile hydrolysis and methacrylic acid hydrogenation. The oxidation of 2-methyl-1-nitropropane to prepare isobutyric acid can also obtain a higher yield. The purification of Isobutyric acid can be realized by azeotropic distillation with water, and anhydrous isobutyric acid can be obtained by the extractive distillation from carbon tetrachloride. Propylene and formic acid ester can react at 50 °C with the catalysis of hydrofluoric acid to generate methyl isobutyrate and propyl isobutyrate.
Purification Methods
Distil the acid from KMnO4, then redistil it from P2O5. [Beilstein 2 H 288, 2 I 126, 2 II 257, 2 III 637, 2 IV 843.]
Check Digit Verification of cas no
The CAS Registry Mumber 79-31-2 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 7 and 9 respectively; the second part has 2 digits, 3 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 79-31:
(4*7)+(3*9)+(2*3)+(1*1)=62
62 % 10 = 2
So 79-31-2 is a valid CAS Registry Number.
InChI:InChI=1/2C4H8O2/c2*1-3(2)4(5)6/h2*3H,1-2H3,(H,5,6)
79-31-2Relevant articles and documents
-
Simons,Werner
, p. 1356 (1942)
-
Brauchbar,Kohn
, p. 16 (1898)
Aqueous Persistent Noncovalent Ion-Pair Cooperative Coupling in a Ruthenium Cobaltabis(dicarbollide) System as a Highly Efficient Photoredox Oxidation Catalyst
Guerrero, Isabel,Vi?as, Clara,Fontrodona, Xavier,Romero, Isabel,Teixidor, Francesc
, p. 8898 - 8907 (2021/06/28)
An original cooperative photoredox catalytic system, [RuII(trpy)(bpy)(H2O)][3,3′-Co(1,2-C2B9H11)2]2 (C4; trpy = terpyridine and bpy = bipyridine), has been synthesized. In this system, the photoredox metallacarborane catalyst [3,3′-Co(1,2-C2B9H11)2]- ([1]-) and the oxidation catalyst [RuII(trpy)(bpy)(H2O)]2+ (C2′) are linked by noncovalent interactions and not through covalent bonds. The noncovalent interactions to a large degree persist even after water dissolution. This represents a step ahead in cooperativity avoiding costly covalent bonding. Recrystallization of C4 in acetonitrile leads to the substitution of water by the acetonitrile ligand and the formation of complex [RuII(trpy)(bpy)(CH3CN)][3,3′-Co(1,2-C2B9H11)2]2 (C5), structurally characterized. A significant electronic coupling between C2′ and [1]- was first sensed in electrochemical studies in water. The CoIV/III redox couple in water differed by 170 mV when [1]- had Na+ as a cation versus when the ruthenium complex was the cation. This cooperative system leads to an efficient catalyst for the photooxidation of alcohols in water, through a proton-coupled electron-transfer process. We have highlighted the capacity of C4 to perform as an excellent cooperative photoredox catalyst in the photooxidation of alcohols in water at room temperature under UV irradiation, using 0.005 mol % catalyst. A high turnover number (TON = 20000) has been observed. The hybrid system C4 displays a better catalytic performance than the separated mixtures of C2′ and Na[1], with the same concentrations and ratios of Ru/Co, proving the history relevance of the photocatalyst. Cooperative systems with this type of interaction have not been described and represent a step forward in getting cooperativity avoiding costly covalent bonding. A possible mechanism has been proposed.
Time-Dependent Self-Assembly of Copper(II) Coordination Polymers and Tetranuclear Rings: Catalysts for Oxidative Functionalization of Saturated Hydrocarbons
Costa, Ines F. M.,Kirillova, Marina V.,André, Vania,Fernandes, Tiago A.,Kirillov, Alexander M.
supporting information, p. 14491 - 14503 (2021/07/19)
This study describes a time-dependent self-assembly generation of new copper(II) coordination compounds from an aqueous-medium reaction mixture composed of copper(II) nitrate, H3bes biobuffer (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), ammonium hydroxide, and benzenecarboxylic acid, namely, 4-methoxybenzoic (Hfmba) or 4-chlorobenzoic (Hfcba) acid. Two products were isolated from each reaction, namely, 1D coordination polymers [Cu3(μ3-OH)2(μ-fmba)2(fmba)2(H2O)2]n (1) or [Cu2(μ-OH)2(μ-fcba)2]n (2) and discrete tetracopper(II) rings [Cu4(μ-Hbes)3(μ-H2bes)(μ-fmba)]·2H2O (3) or [Cu4(μ-Hbes)3(μ-H2bes)(μ-fcba)]·4H2O (4), respectively. These four compounds were obtained as microcrystalline air-stable solids and characterized by standard methods, including the single-crystal X-ray diffraction. The structures of 1 and 2 feature distinct types of metal-organic chains driven by the μ3- or μ-OH- ligands along with the μ-benzenecarboxylate linkers. The structures of 3 and 4 disclose the chairlike Cu4 rings assembled from four μ-bridging and chelating aminoalcoholate ligands along with μ-benzenecarboxylate moieties playing a core-stabilizing role. Catalytic activity of 1-4 was investigated in two model reactions, namely, (a) the mild oxidation of saturated hydrocarbons with hydrogen peroxide to form alcohols and ketones and (b) the mild carboxylation of alkanes with carbon monoxide, water, and peroxodisulfate to generate carboxylic acids. Cyclohexane and propane were used as model cyclic and gaseous alkanes, while the substrate scope also included cyclopentane, cycloheptane, and cyclooctane. Different reaction parameters were investigated, including an effect of the acid cocatalyst and various selectivity parameters. The obtained total product yields (up to 34% based on C3H8 or up to 47% based on C6H12) in the carboxylation of propane and cyclohexane are remarkable taking into account an inertness of these saturated hydrocarbons and low reaction temperatures (50-60 °C). Apart from notable catalytic activity, this study showcases a novel time-dependent synthetic strategy for the self-assembly of two different Cu(II) compounds from the same reaction mixture.
