539-90-2

Basic information

• Product Name: Isobutyl butyrate
• Synonyms: 2-methyl-1-butylbutanoate;Butanoic acid, methyl propyl ester;Butanoicacid,2-methylpropylester;butanoicacid2-methylpropylester;Butyric acid, isobutyl ester;butyricacid,isobutylester;butyricacidisobutylester;Isobutyl ester of butanoic acid
• CAS NO: 539-90-2
• Molecular Formula: C₈H₁₆O₂
• Molecular Weight: 144.21
• EINECS: 208-729-8
• Product Categories: Alphabetical Listings;Certified Natural ProductsFlavors and Fragrances;Flavors and Fragrances;I-L
• Mol File: 539-90-2.mol
• Article Data: 7

Chemical Properties

• Melting Point: -88.07°C (estimate)
• Boiling Point: 157-158 °C(lit.)
• Flash Point: 114 °F
• Appearance: Colorless liquid
• Density: 0.861 g/mL at 25 °C(lit.)
• Vapor Density: 5 (vs air)
• Vapor Pressure: 2.91mmHg at 25°C
• Refractive Index: n20/D 1.403(lit.)
• Merck: 14,5136
• CAS DataBase Reference: Isobutyl butyrate(CAS DataBase Reference)
• NIST Chemistry Reference: Isobutyl butyrate(539-90-2)
• EPA Substance Registry System: Isobutyl butyrate(539-90-2)

Safety Data

• Hazard Codes: N
• Statements: 10-50/53-52/53
• Safety Statements: 16-27-36/37/39-61-60
• RIDADR: UN 3272 3/PG 3
• WGK Germany: 2
• RTECS: ET5020000
• HazardClass: 3.2
• PackingGroup: III
• Hazardous Substances Data: 539-90-2(Hazardous Substances Data)

Usage

Usee

Isobutyl butyrate is a metabolite of Rifampicin, a Rifamycin antibiotic.

Description

Isobutyl butyrate has a fruity odor reminiscent of apple or pineapple and a sweet flavor reminiscent of rum. May be prepared by esterification of butyric acid with isobutyl alcohol in the presence of concentrated H2S04; or by enzymatic action of hog pancreas on a mixture of isobutyl alcohol and butyric acid in the absence of water.

Chemical Properties

Isobutyl butyrate has a fruity, ethereal odor reminiscent of apple or pineapple and a sweet flavor reminiscent of rum.

Definition

ChEBI: A butyrate ester resulting from the formal condensation of butanoic acid with isobutanol. It is used as a food flavour ingredient for apple, banana, peach and pinapple flavours in ice cream and confectionery.

Preparation

By esterification of butyric acid with isobutyl alcohol in the presence of concentrated H2SO4, or by enzymatic action of hog pancreas on a mixture of isobutyl alcohol and butyric acid in the absence of water.

Taste threshold values

Taste characteristics at 20 ppm: sweet, fruity, pineapple, apple, bubble gum and tutti-frutti. Natural occurrence: Reported found in apricot, banana, apple, strawberry, blue and Gruyere cheeses, cognac, port wine, rum, honey, olive, passion fruit, plum, beans, mushrooms, mango, apple brandy, quince, cherimoya, kiwifruit and Chinese quince pee

Synthesis Reference(s)

The Journal of Organic Chemistry, 56, p. 5307, 1991 DOI: 10.1021/jo00018a019

General Description

Isobutyl butyrate is an aliphatic ester that can be used as a food flavoring agent. It is one of the volatile flavor compounds produced in ripening bananas.

Safety Profile

Mdly toxic by ingestion and intraduodenal routes. A skin irritant. See also ESTERS. When heated to decomposition it emits acrid smoke and irritating fumes.

InChI:InChI=1/C8H16O2/c1-4-5-8(9)10-6-7(2)3/h7H,4-6H2,1-3H3

Upstream product

• 106-31-0 butanoic acid anhydride 
• 5674-02-2 2-methylpropylmagnesium chloride 
• 107-92-6 butyric acid 
• 543-27-1 isobutyl chloroformate 
• 123-72-8 butyraldehyde 
• 78-84-2 isobutyraldehyde 
• 20266-12-0 1-butoxy-1-isobutoxy butane 
• 13002-16-9 n-butyraldehyde diisobutyl acetal 
• 78-83-1 2-methyl-propan-1-ol 
• 141-75-3 butyryl chloride 

Downstream Products

• 73545-15-0 isobutyl trans-crotonate 
• 76754-50-2 2-methylpropyl (Z)-but-2-enoate 
• 109-74-0 propyl cyanide 
• 541-35-5 butanamide 

Relevant articles and documents

Total Synthesis and Functional Evaluation of Fourteen Derivatives of Lysocin E: Importance of Cationic, Hydrophobic, and Aromatic Moieties for Antibacterial Activity

Lysocin E (1) is a structurally complex 37-membered depsipeptide comprising 12 amino-acid residues with an N-methylated amide and an ester linkage. Compound 1 binds to menaquinone (MK) in the bacterial membrane to exert its potent bactericidal activity. To decipher the biologically important functionalities within this unique antibiotic, we performed a comprehensive structure-activity relationship (SAR) study by systematically changing the side-chain structures of l-Thr-1, d-Arg-2, N-Me-d-Phe-5, d-Arg-7, l-Glu-8, and d-Trp-10. First, we achieved total synthesis of the 14 new side-chain analogues of 1 by employing a solid-phase strategy. We then evaluated the MK-dependent liposomal disruption and antimicrobial activity against Staphylococcus aureus by 1 and its analogues. Correlating data between the liposome and bacteria experiments revealed that membrane lysis was mainly responsible for the antibacterial functions. Altering the cationic guanidine moiety of d-Arg-2/7 to a neutral amide, and the C7-acyl group of l-Thr-1 to the C2 or C11 counterpart decreased the antimicrobial activities four- or eight-fold. More drastically, chemical mutation of d-Trp-10 to d-Ala-10 totally abolished the bioactivities. These important findings led us to propose the biological roles of the side-chain functionalities.

The Mechanism of the β-Acyloxyalkyl Radical Rearrangement: Kinetic and 18O-Labelling Studies

Experiments with 18O-enriched substrates indicate that the rearrangement of 2-butanoyloxy-2,2-dimethyl radical 1 (R=Pr) by migration of the acyloxy group involves complete transposition of the ether and carbonyl oxygen atoms, whereas the similar but much faster rearrangement of the substituted cholestanyl radical 11 proceeds with only 24percent transposition.The rearrangement of 1 is considered to involve a five-membered cyclic transition state 2, while that of 11 probably proceeds via a tight anion-radical-cation pair 21.

CATALYSED LIQUID PHASE OXIDATION OF ACETALS BY MOLECULAR OXYGEN

Nine different acetals have been oxidized in the presence of Co(OOCCH3)2*4H2O under isobaric conditions (0.1 - 0.2 MPa O2) while following the uptake of molecular oxygen.The reactivity of acetals was expressed by the rate constants of the autocatalytic model of oxidation.The main product of the oxidation are alcohols, esters and acids.The distribution of products and the total reactivity of acetals are controlled by the structure of both parts of acetal molecule.The dominant effects of the course of the reaction exerts the type of carbon atoms on which radicals are formed.The oxidation is accompanied by consecutive and co-oxidation reactions, by deactivation of the catalysts and by decarbonylation of intermediate products.The effect of oxygen pressure is reported and the more detailed radical mechanism of the oxidation is proposed.