759-05-7

Basic information

• Product Name: 3-METHYL-2-OXOBUTYRIC ACIDDISCONTINUED
• Synonyms: 3-methyl-2-oxo-butanoicaci;alpha-ketoisovalerate;3-METHYL-2-OXOBUTYRIC ACIDDISCONTINUED;2-oxoisovaleric acid;2-Ketoisovaleric acid;Butanoic acid, 3-methyl-2-oxo-;3-methyl-2-oxo-butanoic acid;a-Ketoisovaleric acid
• CAS NO: 759-05-7
• Molecular Formula: C₅H₈O₃
• Molecular Weight: 116.11522
• EINECS: 212-065-4
• Mol File: 759-05-7.mol
• Article Data: 44

Chemical Properties

• Melting Point: 31.5℃
• Boiling Point: 170.5℃
• Flash Point: 71 °C
• Appearance: /
• Density: 0.9968
• Refractive Index: 1.3850
• Storage Temp.: 2-8°C
• PKA: 2.57±0.54(Predicted)
• Water Solubility: 400.6g/L(20 oC)
• CAS DataBase Reference: 3-METHYL-2-OXOBUTYRIC ACIDDISCONTINUED(CAS DataBase Reference)
• NIST Chemistry Reference: 3-METHYL-2-OXOBUTYRIC ACIDDISCONTINUED(759-05-7)
• EPA Substance Registry System: 3-METHYL-2-OXOBUTYRIC ACIDDISCONTINUED(759-05-7)

Safety Data

• Hazardous Substances Data: 759-05-7(Hazardous Substances Data)

Usage

Definition

ChEBI: A 2-oxo monocarboxylic acid that is the 2-oxo derivative of isovaleric acid.

Synthesis Reference(s)

The Journal of Organic Chemistry, 28, p. 3088, 1963Tetrahedron Letters, 19, p. 4809, 1978 DOI: 10.1016/S0040-4039(01)85738-5

InChI:InChI=1/C5H8O3/c1-3(2)4(6)5(7)8/h3H,1-2H3,(H,7,8)

Synthetic route

ethyl 3-methyl-2-oxobutanoate (20201-24-5) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With water; lithium hydroxide at 0 - 25℃; for 1h; Inert atmosphere;	95%
With sodium hydroxide In water at 0 - 23℃; for 0.666667h;	62%
With potassium hydroxide

4-isopropylidene-oxazolidine-2,5-dione (7682-64-6) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With sodium hydroxide In tetrahydrofuran for 0.5h; Ambient temperature;	95%

2,5-dihydro-4-(1-methylethyl)-2-(3-oxocyclohexyl)-oxazol-5-one (152343-06-1) → 3-methyl-2-ketobutanoic acid (759-05-7) + 3-oxocyclohexanecarbaldehyde (69814-26-2)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 84%

methyl 2,5-dihydro-4-(1-methylethyl)-γ,5-dioxo-2-oxazol-undecanoate (152343-05-0) → 3-methyl-2-ketobutanoic acid (759-05-7) + 11-formyl-9-oxo-undecanoic acid methyl ester (50266-44-9)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 80%

2,5-dihydro-4-(1-methylethyl)-5-oxo-2-(3-oxobutyl)-oxazol-5-one (152343-03-8) → 4-oxopentanal (626-96-0) + 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A 76% B n/a

methyl 2,5-dihydro-4-(1-methylethyl)-5-oxo-2-oxazol-propionate (152343-04-9) → 3-methyl-2-ketobutanoic acid (759-05-7) + 4-oxobutanoic acid methyl ester (13865-19-5)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 72%

2,5-dihydro-4-(1-methylethyl)-2-(3-oxocyclopentyl)-oxazol-5-one (152343-07-2) → 3-methyl-2-ketobutanoic acid (759-05-7) + 3-formylcyclopentanone (77852-95-0, 65550-06-3)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 70%

2-trifluoromethyl-4-isopropyl-Δ3-oxazolin-5-one (2357-39-3) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With water; sodium hydroxide at 20℃; for 12h; Inert atmosphere;	69%

2,5-dihydro-4-(1-methylethyl)-2-(2-nitroethyl)-oxazol-5-one (152343-08-3) → 3-methyl-2-ketobutanoic acid (759-05-7) + 3-nitropropanaldehyde (58657-26-4)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 64%

2-[((R)-2,2-Dimethyl-[1,3]dioxolan-4-yl)-hydroxy-methyl]-4-isopropyl-2H-oxazol-5-one → 3-methyl-2-ketobutanoic acid (759-05-7) + D-erythrose (583-50-6)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 59%

2,5-dihydro-4-(1-methylethyl)-5-oxo-2-(α-phenyl)-oxazolemethanol → 3-methyl-2-ketobutanoic acid (759-05-7) + (2-Oxo-1-phenyl-ethoxy)-phenyl-acetaldehyde

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 51%

2-[Hydroxy-((S)-2-phenyl-[1,3]dioxan-4-yl)-methyl]-4-isopropyl-2H-oxazol-5-one → L-erythro-4-deoxy-pentose (18439-27-5) + 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A 49% B n/a

2,5-dihydro-2-(1-hydroxyethyl)-4-(1-methylethyl)-oxazol-5-one → 3-methyl-2-ketobutanoic acid (759-05-7) + 2-(1-Methyl-2-oxo-ethoxy)-propionaldehyde

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 44%

2,5-dihydro-4-(1-methylethyl)-5-oxo-2-oxazol-propionic aldehyde → butanedial (638-37-9) + 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A 38% B n/a

2,5-dihydro-4-(1-methylethyl)-5-oxo-2-<α-(2-nitrophenyl)>-oxazolemethanol → 3-methyl-2-ketobutanoic acid (759-05-7) + (2-Nitro-phenyl)-[1-(2-nitro-phenyl)-2-oxo-ethoxy]-acetaldehyde

Conditions	Yield
With hydrogenchloride In tetrahydrofuran Ambient temperature;	A n/a B 37%

pyridine (110-86-1) + tetrachloromethane (56-23-5) + N-Bromosuccinimide (128-08-5) + 2-hydroxy-3-methylbutanenitrile (15344-34-0) → 3-methyl-2-ketobutanoic acid (759-05-7) + isobutyraldehyde (78-84-2)

tetrachloromethane (56-23-5) + 2-bromo-3-methyl-crotonic acid (1578-14-9) → (E)-4-hydroxy-3-methylbut-2-enoic acid (44647-19-0) + 3-methyl-2-ketobutanoic acid (759-05-7) + 2-hydroxy-3-methylbut-3-enoic acid (91496-47-8)

Conditions	Yield
at 100℃;

tetrachloromethane (56-23-5) + 2-hydroxy-3-methylbut-3-enoic acid (91496-47-8) → 3-methyl-2-ketobutanoic acid (759-05-7)

5-methyl-3-hexene-2-one (5166-53-0) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With potassium permanganate
With permanganate(VII) ion Oxydation;

L-valine (72-18-4) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With sodium hydroxide; potassium hexacyanoferrate(III) In water at 55℃; Rate constant; Kinetics; Mechanism; var. reagents conc.;
With potassium nitrososulfonate In various solvent(s) at 26.9℃; Thermodynamic data; Rate constant; ΔH (activ.), ΔS (activ.);
With kidneys-extracts

D,L-valine (516-06-3) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With kidneys-extracts
With perchloric acid; hexachloroiridate(IV) at 34.9℃; Rate constant; Kinetics; Thermodynamic data; var. temp.; ΔH(excit.), ΔG(excit.), ΔS(excit.);
With pyridine-4-carbaldehyde; hydrogenchloride; 1,8-diazabicyclo[5.4.0]undec-7-ene 1.) DMF, r.t., 5 h; Yield given. Multistep reaction;
Multi-step reaction with 2 steps 1: (heating) 2: aq. NaOH View Scheme
With ω-transaminase

2-hydroxy-3-methylbutanoic acid (4026-18-0, 17407-55-5, 17407-56-6, 600-37-3) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With Fructose 1,6-bisphosphate; Bacillus stearothermophilus; triethanolamine hydrochloride; NADH at 25℃; Rate constant; Equilibrium constant; also in presence of Gln102 or Asn enzyme;
With potassium hydroxide; potassium permanganate at 20℃;

isobutyryl cyanide (42867-39-0) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With hydrogenchloride

2,5-Dimethyl-4-hexen-3-ol (60703-31-3) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With potassium permanganate

α-chloro β-dimethyl acrylic acid (15052-93-4) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With sodium hydroxide

2-bromo-3-methyl-crotonic acid (1578-14-9) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With sodium hydroxide

2-isopropyl-5-methyl-hex-2-enal (35158-25-9) → 3-methylbutyric acid (503-74-2) + 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With potassium permanganate

dimethyl-oxalacetic acid (7346-12-5) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With water; copper(II) ion Decarboxylation.pH 2-7;
With aluminium(III) ion; water Decarboxylation.pH 2-7;
With water; nickel(II) Decarboxylation.pH 2-7;
With water; manganese(II) Decarboxylation.pH 2-7;
at 25℃; Kinetics; Wss. Loesungen vom pH 0 bis pH 9, auch in Gegenwart verschiedener Metall-Ionen..Decarboxylation;

diethyl 3,3-dimethyl-2-ketosuccinate (5447-64-3) → 3-methyl-2-ketobutanoic acid (759-05-7)

Conditions	Yield
With sulfuric acid
With hydrogenchloride
With hydrogen bromide; acetic acid

Sucrose (57-50-1) → 3-methyl-2-ketobutanoic acid (759-05-7) + 2-oxo-propionic acid (127-17-3)

Conditions	Yield
With ammonium salts; Aspergillus niger; sulfite(2-)

3-methyl-2-ketobutanoic acid (759-05-7) + Acetanilid (103-84-4) → N-(2-iso-butyrylphenyl)acetamide (1239986-59-4)

Conditions	Yield
With ammonium peroxydisulfate; palladium(II) trifluoroacetate In diethylene glycol dimethyl ether at 20℃;	93%

3-methyl-2-ketobutanoic acid (759-05-7) + (R)-3-((2S,3S)-3-Amino-2-hydroxy-4-phenyl-butyryl)-thiazolidine-4-carboxylic acid tert-butylamide; hydrochloride → (R)-3-[(2S,3S)-2-Hydroxy-3-(3-methyl-2-oxo-butyrylamino)-4-phenyl-butyryl]-thiazolidine-4-carboxylic acid tert-butylamide

Conditions	Yield
With 1-hydroxybenzotriazol-hydrate; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine	89%

3-methyl-2-ketobutanoic acid (759-05-7) → calcium 3-methyl-2-oxobutanoate

Conditions	Yield
Stage #1: 3-methyl-2-ketobutanoic acid With pyrographite; potassium hydroxide In water pH=7; Reflux; Large scale; Stage #2: With calcium chloride In water at 0.2℃; for 3h; Solvent; Reagent/catalyst; Reflux; Large scale;	87.5%

3-methyl-2-ketobutanoic acid (759-05-7) → (S)-2-Hydroxy-3-methylbutanoic acid (17407-55-5)

Conditions	Yield
With NAD; hydrogen In hydrogenchloride for 42h; Ambient temperature;	86%

diazomethane (186581-53-3, 908094-01-9) + 3-methyl-2-ketobutanoic acid (759-05-7) → methyl 3-methyl-2-ketobutanoate (3952-67-8)

Conditions	Yield
In diethyl ether at 0℃;	84%

3-methyl-2-ketobutanoic acid (759-05-7) + 4-methoxybenzoic acid hydrazide (3290-99-1) → 2-(4-Methoxybenzoylhydrazono)-3-methylbuttersaeure (152332-37-1)

Conditions	Yield
With hydrogenchloride In ethanol; water at 60℃; for 2h;	84%

3-methyl-2-ketobutanoic acid (759-05-7) + potassium phenyltrifluoborate → phenyl isopropyl ketone (611-70-1)

Conditions	Yield
With dipotassium peroxodisulfate; palladium diacetate In water; dimethyl sulfoxide at 20℃; for 3h;	83%

3-methyl-2-ketobutanoic acid (759-05-7) + (S)-tert-butyl 2-(hydroxyamino)-3-methylbutanoate (1124196-10-6) → tert-butyl 2-(N-hydroxy-3-methyl-2-oxobutanamido)-3-methylbutanoate

Conditions	Yield
Stage #1: 3-methyl-2-ketobutanoic acid With oxalyl dichloride; N,N-dimethyl-formamide In dichloromethane at 20℃; for 15h; Inert atmosphere; Stage #2: (S)-tert-butyl 2-(hydroxyamino)-3-methylbutanoate With sodium carbonate In dichloromethane; water at 20℃; for 30h; Inert atmosphere;	82%

3-methyl-2-ketobutanoic acid (759-05-7) + 3-Phenylpropenol (104-54-1) → cinnamyl 3-methyl-2-oxobutanoate

Conditions	Yield
With dmap; dicyclohexyl-carbodiimide In dichloromethane	80%

3-methyl-2-ketobutanoic acid (759-05-7) + 2-(aminocarbonyl)-1-pyrrolidinecarboxylic acid, phenylmethyl ester (93188-01-3) → Z-Pro-Δ Val (113586-10-0)

Conditions	Yield
toluene-4-sulfonic acid In benzene for 10h; Heating;	75%

3-methyl-2-ketobutanoic acid (759-05-7) + (S)-2-amino-3-phenylpropionamide hydrochloride (65864-22-4) → N-2-oxo-3-methylbutanoyl-L-phenylalanine amide

Conditions	Yield
Stage #1: (S)-2-amino-3-phenylpropionamide hydrochloride With triethylamine In dichloromethane at 4℃; Stage #2: 3-methyl-2-ketobutanoic acid With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 4 - 20℃; for 2.5h;	74%

allyltrichlorosilane (107-37-9) + 3-methyl-2-ketobutanoic acid (759-05-7) → 2-hydroxy-2-isopropyl-pent-4-enoic acid

Conditions	Yield
With N,N,N,N,N,N-hexamethylphosphoric triamide; N,N-dimethyl-formamide In tetrahydrofuran at 20℃; for 15h; Addition;	73%

3-methyl-2-ketobutanoic acid (759-05-7) + benzoic acid hydrazide (613-94-5) → 2-Benzoylhydrazono-3-methylbuttersaeure (173973-79-0)

Conditions	Yield
In water at 65℃; for 2h;	70%

3-methyl-2-ketobutanoic acid (759-05-7) + methyl S-((3R,5R)-5-hydroxyoctan-3-yl)-L-cysteinate → methyl S-((3R,5R)-5-hydroxyoctan-3-yl)-N-(3-methyl-2-oxobutanoyl)-L-cysteinate

Conditions	Yield
With dmap; dicyclohexyl-carbodiimide In diethyl ether at 0 - 23℃; for 18h;	70%

C6H4NCH2CHCCH2 (491-35-0) + 3-methyl-2-ketobutanoic acid (759-05-7) → 2-isopropyl-4-methylquinoline (91879-71-9)

Conditions	Yield
With (4s,6s)-2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile; tetraethylammonium hexafluorophosphate; trifluoroacetic acid In acetonitrile at 50℃; Schlenk technique; Electrochemical reaction; Irradiation; Inert atmosphere;	68%

3-methyl-2-ketobutanoic acid (759-05-7) + O-benzyl carbamate (621-84-1) → 2-(((benzyloxy)carbonyl)amino)-3-methylbut-2-enoic acid (95863-98-2)

Conditions	Yield
With toluene-4-sulfonic acid In benzene at 99.85℃; for 8h;	67%
With toluene-4-sulfonic acid In benzene at 100℃; for 8h;	67%
With toluene-4-sulfonic acid In benzene at 100℃; for 8h;	67%

3-methyl-2-ketobutanoic acid (759-05-7) + phenylhydrazine (100-63-0) → phenyl isopropyl ketone (611-70-1)

Conditions	Yield
With oxygen; silver(I) acetate; lithium carbonate In 1,2-dichloro-ethane at 100℃; under 760.051 Torr; for 16h; Schlenk technique; Green chemistry;	67%

1,4-pyrazine (290-37-9) + 3-methyl-2-ketobutanoic acid (759-05-7) → 2-methyl-1-(pyrazin-2-yl)propan-1-one (86461-66-7)

Conditions	Yield
With ferrous(II) sulfate heptahydrate; ammonium peroxydisulfate; formic acid; dimethyl sulfoxide In dichloromethane; water at 40℃; Minisci Aromatic Substitution;	65%

3-methyl-2-ketobutanoic acid (759-05-7) + 2-Hydrazino-2-thiazolin-hydrobromid (2643-92-7) → 2,3-Dihydro-6-isopropyl-5H-thiazolo<2,3-c><1,2,4>-triazin-5-on (90516-89-5)

Conditions	Yield
With sodium ethanolate In ethanol for 18h; Heating;	64%

4-Octyne (1942-45-6) + 3-methyl-2-ketobutanoic acid (759-05-7) → (Z)-3-isopropyl-4-propyl-5-propylidenefuran-2(5H)-one

Conditions	Yield
With tetrakis(acetonitrile)copper(I)tetrafluoroborate In toluene at 130℃; for 20h; Inert atmosphere; Sealed tube; diastereoselective reaction;	64%

3-methyl-2-ketobutanoic acid (759-05-7) + methyl S-((3R,5S)-5-hydroxyoctan-3-yl)-L-cysteinate → methyl S-((3R,5S)-5-hydroxyoctan-3-yl)-N-(3-methyl-2-oxobutanoyl)-L-cysteinate

Conditions	Yield
With dmap; dicyclohexyl-carbodiimide In diethyl ether at 0 - 23℃; for 18h;	62%

Upstream product

• 329-07-7 4-isopropyl-2-trifluoromethyl-4H-oxazol-5-one 
• 52316-70-8 N-chloro-L-valine 
• 7664-93-9 sulfuric acid 
• 4374-53-2 3,3-dimethyl-oxirane-2-carboxylic acid 
• 7732-18-5 water 
• 96305-22-5 dihydro-4,4-dimethyl-5-(1-methylethyl)-2,3-furandione 
• 19771-59-6 rac. N,N-Dimethyl-Ile-Val-α-dehydro-Val-Trp-methylester 
• 70159-41-0 3-Methyl-2-(toluene-4-sulfonyloxy)-but-2-enoic acid 
• 57-50-1 Sucrose 
• 1578-14-9 2-bromo-3-methyl-crotonic acid 
• 15052-93-4 α-chloro β-dimethyl acrylic acid 
• 60703-31-3 2,5-dimethyl-2-hexen-4-ol 
• 42867-39-0 isobutyryl cyanide 
• 4026-18-0 2-hydroxy-3-methylbutanoic acid 

Downstream Products

• 101105-77-5 N-(α-oxo-isovaleryl)-L-phenylalanine methyl ester 
• 4026-18-0 2-hydroxy-3-methylbutanoic acid 
• 78-84-2 isobutyraldehyde 
• 90940-33-3 (2R,4S)-pantolactone-4-d1 
• 90940-34-4 (2R,4R)-pantolactone-4-d1 
• 152332-37-1 2-(4-Methoxybenzoylhydrazono)-3-methylbuttersaeure 
• 104197-46-8 2-(2,4-Dinitro-phenyl)-5,5-dimethyl-2,5-dihydro-1H-[1,2,3]triazole-4-carboxylic acid 
• 100718-81-8 N-Dimethylpyruvoyl-glycin-benzylester 
• 100372-91-6 N-Dimethylpyruvoyl-glycin-thiophenylester 
• 100718-58-9 N-(3-methyl-2-oxo-butyryl)-thioalanine S-phenyl ester 
• 173973-79-0 2-Benzoylhydrazono-3-methylbuttersaeure 
• 79-31-2 isobutyric Acid 
• 89598-60-7 5-Hydroxy-3-mercapto-6-isopropyl-1,2,4-triazin 
• 100718-67-0 N-(α-oxo-isovaleryl)-L-phenylalanine 

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