115-19-5

Basic information

• Product Name: 3-Methyl butynol
• Synonyms: 3-methyl-1-butyn-3-o;3-Methyl-butin-(1)-ol-(3);alpha,alpha-Dimethylpropargyl alcohol;alpha,alpha-dimethylpropargylalcohol;Carbavane;Dimethylacetylenecarbinol;Dimethylacetylenylcarbinol;Dimethylethynylmethanol
• CAS NO: 115-19-5
• Molecular Formula: C₅H₈O
• Molecular Weight: 84.12
• EINECS: 204-070-5
• Product Categories: Acetylenes;Acetylenic Alcohols & Their Derivatives;Chemistry;Alkynes;Building Blocks;Chemical Synthesis;Organic Building Blocks;Terminal
• Mol File: 115-19-5.mol
• Article Data: 38

Chemical Properties

• Melting Point: 3 °C
• Boiling Point: 104 °C(lit.)
• Flash Point: 77 °F
• Appearance: White to yellow-beige to brown/Powder or Crystals
• Density: 0.868 g/mL at 25 °C(lit.)
• Vapor Pressure: 15 mm Hg ( 20 °C)
• Refractive Index: n20/D 1.42(lit.)
• Storage Temp.: Flammables area
• Solubility: Fully miscible.
• PKA: 13.34±0.29(Predicted)
• Explosive Limit: 1.8-16%(V)
• Water Solubility: miscible
• Stability: Stable. Flammable. Incompatible with strong oxidizing agents.
• Merck: 14,6034
• BRN: 635746
• CAS DataBase Reference: 3-Methyl butynol(CAS DataBase Reference)
• NIST Chemistry Reference: 3-Methyl butynol(115-19-5)
• EPA Substance Registry System: 3-Methyl butynol(115-19-5)

Safety Data

• Hazard Codes: Xn
• Statements: 10-22-41
• Safety Statements: 26-39-16
• RIDADR: UN 1987 3/PG 2
• WGK Germany: 1
• RTECS: ES0810000
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 115-19-5(Hazardous Substances Data)

Usage

Chemical Properties

colourless to light yellow liquid

Uses

Different sources of media describe the Uses of 115-19-5 differently. You can refer to the following data:
1. Stabilizer in chlorinated solvents, viscosity reducer and stabilizer, electroplating brightener, intermediate.
2. 2-Methyl-3-butyn-2-ol is used as an intermediate in the manufacture of products for the agrochemical and specialty chemical industry.

General Description

Colorless to straw yellow liquid.

Air & Water Reactions

Highly flammable.

Reactivity Profile

3-Methyl butynol is an alcohol. Flammable and/or toxic gases are generated by the combination of alcohols with alkali metals, nitrides, and strong reducing agents. They react with oxoacids and carboxylic acids to form esters plus water. Oxidizing agents convert them to aldehydes or ketones. Alcohols exhibit both weak acid and weak base behavior. They may initiate the polymerization of isocyanates and epoxides.

Hazard

Flammable, dangerous fire risk.

Health Hazard

Contact will cause eye and skin irritation. Vapor exposure may cause eye and respiratory tract irritation.

Fire Hazard

Special Hazards of Combustion Products: Irritating and toxic gases, such as carbon dioxide and carbon monoxide, may be produced in fire.

Flammability and Explosibility

Highlyflammable

Synthetic route

acetone (67-64-1) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With sodium In methanol at 0 - 5℃; for 1h; Solvent; Reagent/catalyst; Autoclave; Inert atmosphere; Large scale;	99.2%
Stage #1: acetylene With sodium amide In ammonia at -50℃; for 0.5h; Stage #2: acetone at -50 - 25℃;	87.9%
Stage #1: acetylene With potassium hydroxide monohydrate In dimethyl sulfoxide at 10 - 15℃; for 7h; Stage #2: acetone In dimethyl sulfoxide at 10 - 15℃; for 9h; Temperature;	82%

polymethyl(3-hydroxy-3-methyl-1-butynyl)siloxane → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With tetrabutyl ammonium fluoride In tetrahydrofuran at 25℃; for 12h;	99%

acetone (67-64-1) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5) + 2,5-dihydroxy-2,5-dimethyl-3-hexyne (142-30-3)

Conditions	Yield
With potassium hydride In tetrahydrofuran at 30℃; under 759.826 Torr; for 2.25h;	A 7% B 91%
Stage #1: acetone; acetylene With potassium 2-methylpropan-2-olate In xylene at 28 - 35℃; for 1h; Stage #2: With water Stage #3: With phosphoric acid Product distribution / selectivity;	A 2.3% B 90%
Stage #1: acetone; acetylene With potassium 2-methylpropan-2-olate In xylene at 10 - 20℃; for 1h; Stage #2: With water Stage #3: With phosphoric acid Product distribution / selectivity;	A 79% B 3%

acetone (67-64-1) + lithium acetylide (70277-75-7) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
Stage #1: acetone; lithium acetylide; 4,4'-di-tert-butylbiphenyl In tetrahydrofuran at 0℃; for 2h; Stage #2: With water In tetrahydrofuran at 20℃; Product distribution / selectivity;	81%
Stage #1: acetone; lithium acetylide; naphthalene In tetrahydrofuran at 0℃; for 2h; Stage #2: With water In tetrahydrofuran at 20℃; Product distribution / selectivity;	56.5%

2-methyl-propan-1-ol (78-83-1) + acetone (67-64-1) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5) + 2,5-dihydroxy-2,5-dimethyl-3-hexyne (142-30-3)

Conditions	Yield
Stage #1: 2-methyl-propan-1-ol With potassium hydride In tetrahydrofuran at 30℃; under 759.826 Torr; for 0.25h; Stage #2: acetone; acetylene In tetrahydrofuran at 30℃; under 759.826 Torr; for 2.25h;	A 74% B 22%

2-methyl-3-butyn-2-ol 1-ethoxyethyl ether (39807-00-6) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With N,4-dimethyl-N-vinylbenzenesulfonamide; picAuCl2(III) In dichloromethane at 20℃; for 0.25h; Inert atmosphere;	60%

acetone (67-64-1) + acetylenemagnesium bromide (4301-14-8) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
In tetrahydrofuran Heating;	47%
Stage #1: acetone; acetylenemagnesium bromide In tetrahydrofuran at 0 - 20℃; Stage #2: With ammonium chloride In tetrahydrofuran; water
In tetrahydrofuran at -10 - 20℃;

4-Hydroxy-4-methyl-2-pentanone (123-42-2) + sodium acetylide (1066-26-8) → 2-methyl-but-3-yn-2-ol (115-19-5)

sodium acetylide (1066-26-8) + acetone (67-64-1) → 2-methyl-but-3-yn-2-ol (115-19-5)

sodium acetylide + acetone (67-64-1) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
at -20℃;
at -20℃;

diethyl ether (60-29-7) + sodium ethanolate (141-52-6) + acetone (67-64-1) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5)

sodium acetylide (1066-26-8) + acetone (67-64-1) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With ammonia
With ammonia

ethylmagnesium bromide (925-90-6) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With diethyl ether nachfolgende Einw. von Aceton;

2,5-dihydroxy-2,5-dimethyl-3-hexyne (142-30-3) → acetone (67-64-1) + 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
Pyrolysis;
With silica gel Pyrolysis;
With calcium carbide Pyrolysis;

3-chloro-3-methylbut-1-yne (1111-97-3) + cyclopenta-1,3-diene (542-92-7) → 2,2-dimethylbicyclo<3.2.1>oct-6-en-3-one (22940-29-0) + 3-Chlor-4,4-dimethylbicyclo<3.2.1>octa-2,6-dien (65404-99-1) + 4-(1,1-Dimethyl-2-propinyl)-2-cyclopenten-1-ol (344257-36-9) + propargyl alcohol (107-19-7) + 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With potassium hydroxide; silver trifluoroacetate In pentane at 0℃; Mechanism;

C12H13F3O2Se → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With 1,4-diaza-bicyclo[2.2.2]octane In benzene at 95℃; for 2h; Yield given;

2-Iodobenzoic acid (88-67-5) → 2-(3-Hydroxy-3-methyl-but-1-ynyl)-benzoic acid (147454-79-3) + (Z)-3-(2-hydroxy-2-methylpropylidene)-3H-isobenzofuran-1-one (147454-71-5) + 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine 1.) DMF, 1 h, 2.) DMF, a) RT, 1 h, b) 30 deg C, 6 h; Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;

diethyl ether (60-29-7) + sodium amide + acetone (67-64-1) + acetylene (74-86-2) → 2-methyl-but-3-yn-2-ol (115-19-5)

acetylene (74-86-2) + acetonevapour → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With sodium amide
auf aether.Suspensionen von Natriumamid,Natrium oder Natriumaethylat;

acetone (67-64-1) + calcium carbide → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With potassium hydroxide; ethanol

acetone (67-64-1) + disodium acetylene → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
at -20℃;

acetylene (74-86-2) + potassium acetone → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With diethyl ether

diethyl ether (60-29-7) + acetylene (74-86-2) + potassium acetone → 2-methyl-but-3-yn-2-ol (115-19-5)

acetone (67-64-1) + potassium acetylenide → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With Dimethoxymethane at 0℃;
With dibutyl acetal at -3℃;
With diethyl acetal; poly ether at -10℃;
With xylene; butan-1-ol at -10℃;
With dibutyl acetal at -3℃;

diethyl ether (60-29-7) + acetone (67-64-1) + acetylene (74-86-2) + potassium → 2-methyl-but-3-yn-2-ol (115-19-5)

acetylene (74-86-2) + sodium acetone → 2-methyl-but-3-yn-2-ol (115-19-5)

Conditions	Yield
With diethyl ether

acetic anhydride (108-24-7) + 2-methyl-but-3-yn-2-ol (115-19-5) → 1,1-dimethyl-2-propynyl acetate (1604-29-1)

Conditions	Yield
tetrafluoroboric acid; silica gel at 20℃; for 2h;	100%
indium(III) chloride at 20℃; for 0.5h;	100%
With magnesium(II) perchlorate at 20℃; for 0.5h;	100%

phenyl isocyanate (103-71-9) + 2-methyl-but-3-yn-2-ol (115-19-5) → O-α,α-dimethylpropargyl N-phenylcarbamate (6289-19-6)

Conditions	Yield
With MoCl2O2(dmf)2 In dichloromethane at 20℃; for 0.333333h;	100%
With triethylamine In tetrahydrofuran at 70℃; for 12h; Inert atmosphere;	94%
With dmap; triethylamine In tetrahydrofuran at 20℃; for 90h;	88%

ethyl vinyl ether (109-92-2) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-methyl-3-butyn-2-ol 1-ethoxyethyl ether (39807-00-6)

Conditions	Yield
With pyridinium p-toluenesulfonate In dichloromethane at 20℃; for 1h;	100%
With sulfuric acid for 0.5h;	77%
With hydrogenchloride

triethylsilyl chloride (994-30-9) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-methyl-2-<(triethylsilyl)oxy>-3-butyne (17963-41-6)

Conditions	Yield
With dmap; triethylamine In dichloromethane at 0℃; for 1h;	100%

2-methyl-but-3-yn-2-ol (115-19-5) + Phenyl azide (622-37-7) → 2-(1-phenyl-1H-1,2,3-triazol-4-yl)-2-propanol (856863-40-6)

Conditions	Yield
With triethylamine In neat (no solvent) at 20℃; for 24h; Huisgen Cycloaddition; Inert atmosphere; Green chemistry; regioselective reaction;	100%
With Cu(OAc)2-anchored mesoporous SBA-15 catalyst (CuSBA-15-PTAA) In water at 50℃; for 6h;	95%
With C39H44ClCuN2(1+) In neat (no solvent) at 25℃; for 1h; Schlenk technique; Inert atmosphere;	94%

2-methyl-but-3-yn-2-ol (115-19-5) + 3-Chloro-2-methylpropene (563-47-3) → 2,6-dimethylhept-6-en-3-yn-2-ol (28246-76-6)

Conditions	Yield
With copper(l) iodide; TEA at 60℃;	100%
With copper(l) iodide; N-benzyl-N,N,N-triethylammonium chloride; potassium carbonate; potassium iodide; sodium sulfite In water; benzene at 75 - 80℃; for 6h;	92%
With potassium carbonate; copper(l) iodide; tetrabutyl-ammonium chloride In N,N-dimethyl-formamide for 16h; Product distribution; Ambient temperature; variation of catalysts and reaction time;	88%

2-methyl-but-3-yn-2-ol (115-19-5) → 2,7-dimethyl-octa-3,5-diyne-2,7-diol (5929-72-6)

Conditions	Yield
With carbon dioxide; sodium acetate; copper dichloride In methanol at 40℃; under 105008 Torr; for 4h;	100%
With copper(l) iodide; ethyl bromoacetate; N-ethyl-N,N-diisopropylamine; bis-triphenylphosphine-palladium(II) chloride In tetrahydrofuran at 20℃;	99%
With oxygen; (TBA)4[γ-H2SiW10O36Cu2(μ-1,1-N3)2] In benzonitrile at 99.84℃; under 760.051 Torr; for 2h;	99%

allyl bromide (106-95-6) + 2-methyl-but-3-yn-2-ol (115-19-5) → (Z)-2-Bromo-1-hydroxy-1-methyl-2,5-hexadiene

Conditions	Yield
bis(acetonitrile)palladium(II) bromide 1) 0 deg C, 0.5-1 h, 2) r.t.;	100%
bis(benzonitrile)palladium(II) bromide In 1,2-dimethoxyethane at 0 - 20℃; for 6h;

bromobenzene (108-86-1) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-Methyl-4-phenyl-3-butyn-2-ol (1719-19-3)

Conditions	Yield
With copper(l) iodide; C80H65BrN2O2P4Pd; triethylamine In water for 7h; Reagent/catalyst; Sonogashira Cross-Coupling; Inert atmosphere; Reflux;	100%
With copper(l) iodide; diethylamine; triphenylphosphine; palladium diacetate for 36h; Heating;	98%
With copper(l) iodide; palladium diacetate; triphenylphosphine; 3-aminopentane for 36h; Inert atmosphere; Reflux;	98%

2-Bromo-6-methoxynaphthalene (5111-65-9) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-methyl-4-(6-methoxynaphthalen-2-yl)but-3-yn-2-ol (129112-99-8)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; diethylamine for 17h; Heating;	100%
With copper(l) iodide; ethanolamine; triphenylphosphine; palladium on activated charcoal In water; acetonitrile at 80℃; for 15h; Sonogashira cross-coupling;	80%
With bis-triphenylphosphine-palladium(II) chloride; copper(I) In triethylamine at 90℃; for 20h;	79%
With tetrakis(triphenylphosphine) palladium(0); triphenylphosphine; lithium bromide; copper(ll) bromide In tetrahydrofuran at 90℃; for 2h; Substitution; Title compound not separated from byproducts;
With copper(l) iodide; palladium diacetate; N-ethyl-N,N-diisopropylamine; triphenylphosphine In N,N-dimethyl-formamide at 70℃; for 12h; Inert atmosphere; Glovebox;

1-trifluoromethanesulfonyloxy-4-t-butylcyclohexene (77412-96-5) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-methyl-4-(4-tert-butylcyclohexenyl)but-3-yn-2-ol (96575-62-1)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; triethylamine In N,N-dimethyl-formamide at 75℃; for 5.5h;	100%

(1,1-dimethylethyl)(3-iodophenoxy)dimethylsilane (133910-12-0) + 2-methyl-but-3-yn-2-ol (115-19-5) → 4-[3-(tert-Butyl-dimethyl-silanyloxy)-phenyl]-2-methyl-but-3-yn-2-ol (188957-22-4)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; diisopropylamine at 75℃; for 16h;	100%

2-methyl-but-3-yn-2-ol (115-19-5) + para-nitrophenyl bromide (586-78-7) → 2-methyl-4-(4-nitrophenyl)but-3-yn-2-ol (33432-53-0)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine In tetrahydrofuran for 12h; Sonogashira Cross-Coupling; Inert atmosphere; Reflux;	100%
With copper(l) iodide; triethylamine; triphenylphosphine at 90℃; for 3h; Sonogashira coupling; Inert atmosphere;	97%
With copper(l) iodide; triethylamine; bis-triphenylphosphine-palladium(II) chloride In tetrahydrofuran for 12h; Heating;	96%

iodobenzene (591-50-4) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-Methyl-4-phenyl-3-butyn-2-ol (1719-19-3)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine at 20℃; for 4h; Sonogashira Cross-Coupling; Inert atmosphere;	100%
With copper(l) iodide; triethylamine; triphenylphosphine at 90℃; for 3h; Sonogashira coupling; Inert atmosphere;	94%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; N,N,N',N'-tetramethylguanidine at 30℃; for 1h; Sonogashira Cross-Coupling; Schlenk technique; Inert atmosphere; Green chemistry;	94%

methyl 4-iodobenzoate (619-44-3) + 2-methyl-but-3-yn-2-ol (115-19-5) → methyl 4-(3-hydroxy-3-methylbut-1-ynyl)benzoate (33577-98-9)

Conditions	Yield
With copper(l) iodide; (Ph3)2PdCl2; triphenylphosphine; triethylamine for 68h; Sonogashira reaction; Heating;	100%
With copper(l) iodide; trans-bis(triphenylphosphine)palladium dichloride; triethylamine at 20℃; Inert atmosphere;	96.07%
With copper(l) iodide; triethylamine; polymer-bound Pt(0)-phoshine In water; acetonitrile at 55℃; for 8h;	95%

4-bromo-benzaldehyde (1122-91-4) + 2-methyl-but-3-yn-2-ol (115-19-5) → 4-(3-hydroxy-3-methylbut-1-ynyl)benzaldehyde (117569-57-0)

Conditions	Yield
With triethylamine; triphenylphosphine; palladium diacetate Substitution;	100%
Stage #1: 4-bromo-benzaldehyde; 2-methyl-but-3-yn-2-ol With copper(l) iodide; tetrakis(triphenylphosphine) palladium(0) In toluene Inert atmosphere; Stage #2: With diisopropylamine In toluene at 20℃; for 24h; Inert atmosphere;	97%
With copper(l) iodide; triethylamine; triphenylphosphine; palladium diacetate In benzene at 75 - 80℃; for 0.666667h;	93%

1-heptyl vinyl ether (764-95-4) + 2-methyl-but-3-yn-2-ol (115-19-5) → 1-[1-(1,1-Dimethyl-prop-2-ynyloxy)-ethoxy]-heptane

Conditions	Yield
With trifluoroacetic acid at 20 - 75℃; Addition;	100%

diethylene glycol divinyl ether (764-99-8) + 2-methyl-but-3-yn-2-ol (115-19-5) → 3-[1-(2-{2-[1-(1,1-dimethyl-prop-2-ynyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-3-methyl-but-1-yne

Conditions	Yield
With trifluoroacetic acid at 20 - 48℃; Addition;	100%

2-methyl-but-3-yn-2-ol (115-19-5) + bis adduct of diethylene glycol divinyl ether and diethylene glycol (273406-64-7) → 3-[1-(2-{2-[1-(2-{2-[1-(2-{2-[1-(1,1-dimethyl-prop-2-ynyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-3-methyl-but-1-yne

Conditions	Yield
With trifluoroacetic acid at 30 - 35℃; for 12h; Addition;	100%

2-methyl-but-3-yn-2-ol (115-19-5) + 8-bromo-3,3-diphenyl-<3H>-naphtho<2,1-b>pyran (227471-78-5) → 8-(3-hydroxy-3-methylbut-1-ynyl)-3,3-diphenyl-3H-naphtho[2,1-b]pyran (327163-55-3)

Conditions	Yield
bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide In diethylamine at 20℃; for 14h;	100%
With copper(l) iodide; diethylamine; bis-triphenylphosphine-palladium(II) chloride at 20℃; for 16h; Sonogashira coupling;	96%

dimethyl (4-nitrobenzylidene)malonate (38323-22-7) + 2-methyl-but-3-yn-2-ol (115-19-5) → 5,5-dimethyl-4-methylene-2-(4-nitro-phenyl)-dihydro-furan-3,3-dicarboxylic acid dimethyl ester

Conditions	Yield
With copper(l) iodide; n-butyllithium In tetrahydrofuran; hexane at 20℃; for 3h;	100%

4-Iodoacetophenone (13329-40-3) + 2-methyl-but-3-yn-2-ol (115-19-5) → 1-(4-acetylphenyl)-3-methyl-1-butyn-3-ol (95785-28-7)

Conditions	Yield
With copper(l) iodide; 1-isobutyl-2,2,6,6-tetramethyl-phosphorinane*HBF4; diisopropylamine; bis(benzonitrile)palladium(II) dichloride In 1,4-dioxane at 20℃; for 6h; Sonogashira reaction;	100%
With piperidine; copper(l) iodide; polystyrene-N(CH2PPh2)2PdCl2 In 1,4-dioxane at 60℃; for 2h; Sonogashira coupling reaction;	94%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine at 20℃; Inert atmosphere;	90%

3-cyanobromobenzene (6952-59-6) + 2-methyl-but-3-yn-2-ol (115-19-5) → 3-(3-hydroxy-3-methylbut-1-ynyl)benzonitrile (766539-54-2)

Conditions	Yield
With triethylamine; bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide at 60℃;	100%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine at 110℃; for 3h;	90%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine at 60℃; for 3h; Sonogashira Cross-Coupling;

2-methyl-but-3-yn-2-ol (115-19-5) + 4-n-butoxy-2,6-dibromopyridine (173314-96-0) → 4-butoxy-2,6-bis(3-hydroxy-3-methyl-1-butynyl)pyridine (675617-47-7)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; diethylamine at 20℃; for 3.5h; Sonogashira coupling;	100%

benzyl bromide (100-39-0) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-propanol (116557-80-3)

Conditions	Yield
With sodium azide In water at 55℃; for 2h; Green chemistry; regioselective reaction;	100%
With sodium azide; bis(2-{phenyliminomethyl}pyrrolato)copper(II) In water at 60℃; for 12h; Schlenk technique; regioselective reaction;	96%
With sodium azide; sodium L-ascorbate In water at 60℃; for 5h;	95%

2-Chloroquinoline (612-62-4) + 2-methyl-but-3-yn-2-ol (115-19-5) → 2-methyl-4-(2′-quinolyl)but-3-yn-2-ol (831235-64-4)

Conditions	Yield
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine at 80℃; for 3h; Sonogashira Cross-Coupling; Inert atmosphere;	100%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine at 80℃; Inert atmosphere;	100%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; diethylamine at 40℃; for 0.5h; Sonogashira Cross-Coupling;	98%

isobutyraldehyde (78-84-2) + 2-methyl-but-3-yn-2-ol (115-19-5) → (R/S)-2,6-dimethylhept-3-yne-2,5-diol (5486-58-8)

Conditions	Yield
Stage #1: 2-methyl-but-3-yn-2-ol With n-butyllithium In tetrahydrofuran; hexane at -40℃; for 0.333333h; Inert atmosphere; Stage #2: isobutyraldehyde With cerium(III) chloride In tetrahydrofuran; hexane Reagent/catalyst;	100%
Stage #1: 2-methyl-but-3-yn-2-ol With n-butyllithium In tetrahydrofuran at -78℃; for 0.333333h; Inert atmosphere; Stage #2: isobutyraldehyde With cerium(III) chloride In tetrahydrofuran at 0℃; Inert atmosphere;	92%
Stage #1: 2-methyl-but-3-yn-2-ol With n-butyllithium In tetrahydrofuran at -78℃; for 2h; Stage #2: isobutyraldehyde In tetrahydrofuran at -65 - 20℃; Further stages.;	81%
Stage #1: 2-methyl-but-3-yn-2-ol With n-butyllithium at -78℃; for 1h; Inert atmosphere; Stage #2: isobutyraldehyde at -78 - 20℃; Inert atmosphere;

2,6-diiodo-4-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-pyridine (917505-64-7) + 2-methyl-but-3-yn-2-ol (115-19-5) → 4-(6-(3-hydroxy-3-methyl-but-1-ynyl)-4-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-pyridin-2-yl)-2-methyl-but-3-yn-2-ol (1029916-41-3)

Conditions	Yield
bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide In diethylamine at 20℃; for 5h; Sonogashira reaction;	100%

4-[ethoxydi(prop-2-enyl)silyl]iodobenzene (959419-50-2) + 2-methyl-but-3-yn-2-ol (115-19-5) → 1-[diallyl(ethoxy)silyl]-4-(3-hydroxy-3-methyl-1-butynyl)benzene

Conditions	Yield
With copper(l) iodide; triethylamine; triphenylphosphine; Pd2(PPh3)2Cl2 In tetrahydrofuran at 50℃; for 1.5h; Sonogashira coupling;	100%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; diethylamine In tetrahydrofuran at 50℃; Sonogashira coupling;

bis(triphenylphosphine)palladium(II) dichloride + 4-iodobenzo[b]thiophene-2-carbonitrile (154629-36-4) + 2-methyl-but-3-yn-2-ol (115-19-5) → 4-(3-hydroxy-3-methylbut-1-ynyl)benzo[b]thiophene-2-carbonitrile (154629-77-3)

Conditions	Yield
With CuI In triethylamine	100%

Upstream product

• 60-29-7 diethyl ether 
• 141-52-6 sodium ethanolate 
• 67-64-1 acetone 
• 74-86-2 acetylene 
• 1066-26-8 sodium acetylide 
• 32449-00-6 acetone; sodium acetone 
• 123-42-2 4-Hydroxy-4-methyl-2-pentanone 
• 88-67-5 2-Iodobenzoic acid 
• 142-30-3 2,5-dihydroxy-2,5-dimethyl-3-hexyne 
• 7732-18-5 water 
• 27822-67-9 1-chloro-3-methyl-buta-1,2-diene 
• 6214-31-9 3-bromo-3-methylbut-1-yne 
• 78-83-1 2-methyl-propan-1-ol 
• 1111-97-3 3-chloro-3-methylbut-1-yne 

Downstream Products

• 25597-36-8 2-(1,1-dimethylprop-2-ynyloxy)ethanol 
• 29871-35-0 2-[2-(1,1-dimethyl-prop-2-ynyloxy)-ethoxy]-ethanol 
• 1604-29-1 1,1-dimethyl-2-propynyl acetate 
• 16647-04-4 6-methyl-3,5-heptadien-2-one 
• 17869-83-9 3-methoxymethoxy-3-methyl-but-1-yne 
• 6322-38-9 2-(2-methyl-1,3-dioxolan-2-yl)propan-2-ol 
• 33243-75-3 <1-Methyl-butin-(3)-yl-(2)>-<2,2,2-trichlor-1-hydroxyethyl>-ether 
• 27068-29-7 2-methylhept-6-en-3-yn-2-ol 
• 15496-08-9 1,1-Dimethyl-2-propyn-1-ol 2-cyanoethyl ether 
• 6289-19-6 O-α,α-dimethylpropargyl N-phenylcarbamate 
• 49633-50-3 3-hydroxy-3-methyl-butan-2-one-phenylimine 
• 23695-53-6 2-methyl-5-phenyl-hex-3-yne-2,5-diol 
• 16900-79-1 2-methyl-6-phenylhexa-3,5-diyn-2-ol 
• 33060-69-4 2-methylbut-3-yn-2-yl carbamate 

Relevant articles and documents

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The role of potassium cation in the Favorskii ethynylation of acetone: Effekt of dibenzo-18-crown-6

Macrocyclic polyether dibenzo-18-crown-6 possessing a specific affinity for potassium cation inhibits ethynylation of acetone with acetylene in the presence of KOH according to Favorskii. The inhibition becomes stronger in the presence of the complex dibenzo-18-crown-6·KOH·MeOH as catalyst (both in excess acetone and in DMSO). The effect does not originate from deactivation of acetone, for its aldol-like condensation is accelerated in the presence of both dibenzo-18-crown-6 and its complex (the selectivity of ethynylation sharply falls down). Thus, apart from the high basicity of the medium, activation of acetylene due to complex formation with potassium cation plays an important role in the Favorskii ethynylation of ketones.

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Separation method of 2-methyl-3-butyn-2-ol

The invention belongs to the technical field of acetylene alcohol production, and particularly relates to a separation method of 2-methyl-3-butyn-2-ol, which comprises the following steps: pretreatinga reaction solution containing 2-methyl-3-butyn-2-ol to remove unreacted acetone and contained salt from the reaction solution to obtain a 2-methyl-3-butyn-2-ol crude product, with the content of 2,5-dimethyl-3-hexyn-2,5-diol in the reaction solution containing 2-methyl-3-butyn-2-ol being not higher than 0.1 wt%; separating and purifying the 2-methyl-3-butyn-2-ol crude product by virtue of membrane separation treatment and reduced pressure distillation treatment, so as to obtain a 2-methyl-3-butyn-2-ol product. According to the method disclosed by the invention, water in the product can be removed and the content of the 2,5-dimethyl-3-hexyn-2,5-diol can be reduced under the condition that the investment and the energy consumption are reduced, so that the 2-methyl-3-butyn-2-ol with relatively high purity and conversion rate is obtained.

Base-Catalyzed Borylation/B-O Elimination of Propynols and B2pin2 Delivering Tetrasubstituted Alkenylboronates

An efficient approach to tetrasubstituted alkenylboronates via a cascade borylation/B-O elimination of propynols and B2pin2 was disclosed. A series of tetrasubstituted alkenylboronates were readily furnished with this strategy in good yields, with further transformations leading to tetrasubstituted alkenes and β-diketones demonstrating the synthetic potential of the alkenylboronates constructed by this strategy as versatile intermediates in organic synthesis.