Name | 3-Methyl-2-buten-1-ol |
Synonyms | Prenol Prenyl alcohol 3-Methyl-2-butenol Isopentenyl Alcohol dimethylallylalcohol 3-methyl-2-buten-1-o 3-Methyl-2-buten-1-ol 3-methylbut-2-en-1-ol 3-methyl-but-2-en-1-ol 3,3-Dimethylallyl alcohol 3-Methyl-2-butenyl alcohol gamma,gamma-dimethylallylalcohol Isoamylene 3-methyl-2-buten-1-ol gamma,gamma-Dimethylallyl alcohol |
CAS | 556-82-1 |
EINECS | 209-141-4 |
InChI | InChI=1/C5H10O/c1-5(2)3-4-6/h3,6H,4H2,1-2H3 |
InChIKey | ASUAYTHWZCLXAN-UHFFFAOYSA-N |
Molecular Formula | C5H10O |
Molar Mass | 86.13 |
Density | 0.848g/mLat 25°C(lit.) |
Melting Point | 43.52°C |
Boling Point | 140°C(lit.) |
Flash Point | 110°F |
JECFA Number | 1200 |
Water Solubility | 170 g/L (20 ºC) |
Solubility | 64g/l |
Vapor Presure | 1.4 mm Hg ( 20 °C) |
Appearance | Liquid |
Color | Clear colorless to very slightly yellow |
BRN | 1633479 |
pKa | 14.83±0.10(Predicted) |
Storage Condition | Sealed in dry,2-8°C |
Explosive Limit | 2.7-16.3%(V) |
Refractive Index | n20/D 1.443(lit.) |
Physical and Chemical Properties | This product is colorless transparent liquid, with strong Ester flavor, B. p.140 ℃(52~56 ℃/2.67kpa),n20D 1.4160, relative density 0.8240, insoluble in water, soluble in alcohol, ether and other organic solvents. |
Hazard Symbols | Xn - Harmful |
Risk Codes | R10 - Flammable R22 - Harmful if swallowed R36/37/38 - Irritating to eyes, respiratory system and skin. R38 - Irritating to the skin R21/22 - Harmful in contact with skin and if swallowed. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S37 - Wear suitable gloves. S23 - Do not breathe vapour. S16 - Keep away from sources of ignition. |
UN IDs | UN 1987 3/PG 3 |
WGK Germany | 1 |
RTECS | EM9472500 |
TSCA | Yes |
HS Code | 29052990 |
Hazard Class | 3 |
Packing Group | III |
FEMA | 3647 | 3-METHYL-2-BUTEN-1-OL |
NIST chemical information | Information provided by: webbook.nist.gov (external link) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
Use | Isopentenol, namely 3-methyl-2-butene-1-ol (3-methyl-2-butene-1-ol), is a colorless and transparent liquid, water-soluble 170g/L, miscible in most organic solvents such as alcohol and ether. It is mainly used to synthesize important precursors of vitamin E, vitamin A, perfume products citral, high-efficiency and low-toxic pesticide pyrethroid insecticides and other products. Isopentenol is mainly used for the synthesis of high-efficiency and low-toxicity pesticide pyrethroid insecticide intermediate benthinate methyl ester, and its downstream products dichlorochrysanthemum acid ester, DV chrysanthemum chloride (dichlorochrysanthemum chloride) And so on, with the continuous research and maturity of the synthesis process of isopentenol, and the continuous deepening of application development, its application scope in pesticides will continue to expand, and the market demand will also increase significantly. Isopentenol is an important raw material for the synthesis of pyrethroid precursor benzoate methyl ester. Isopentenol and trimethyl orthoacetate are usually used in the presence of an acidic catalyst. The condensation Claisen is rearranged to generate methyl benthine acid. Another use of isopentenol is the main intermediate for the production of polycarboxylate superplasticizer raw material TPEG. Isopentenol is an important raw material for the production of polycarboxylate cement water reducer. The use of this high-performance cement water reducer in concrete production and construction can reduce the water consumption by more than 30%, enhance the strength of concrete by more than 30%, and reduce the amount of cement accordingly. 3-Methyl-2-butenol, or isopentenol, is an important intermediate for the synthesis of dichlorochrysanthemum acid. Used in organic synthesis. |
synthesis process | At present, the synthesis process of isopentenol mainly includes: ① using isobutylene and formaldehyde as raw materials through Prins reaction condensation and isomerization two-step synthesis process, this reaction is to enter under ultra-high temperature and ultra-high pressure conditions, which is an unfriendly process in terms of safety and energy consumption; ② isoprene carboxyl ester esterification method is prepared by esterification and rehydrolysis of isoprene and carboxylic acid. this process is gentle, but produces a large amount of three wastes, which is not friendly to the environment good process; ③ isopentenal hydrogenation method, which is mainly limited by the source of raw materials and is difficult for large-scale industrial production; ④ acetone and acetylene are used as raw materials for acetylene, hydrogenation and isomerization synthesis process ·, this process mild reaction conditions, simple operation is the current production of isopentenol mainstream process, but due to many steps, the production cost is high; ⑤ isoprene is the original material direct hydration process, the process product has two isopentenols and 2 -methyl -3-butene-2-ol, 2-Methyl-3-butene-2- Alcohol can be converted into isoprenol by isomerization. |
production method | this product can be obtained by reacting isobutylene with formaldehyde. 95% polyoxymethylene was added to a stainless steel autoclave, disodium hydrogen phosphate was used as catalyst, tert-butanol was added, and then nitrogen was used to replace the air in the reactor, isobutylene was added, heated to 200 ℃ under stirring for 4h, and then cooled and distilled to obtain 3-methyl-2-butenol with a yield of 85%. Isoprene can also be used as raw material to react with hydrogen chloride, and 1-chloro-3-methylbutene-2 can be obtained by transposition. The latter is placed in the reactor and added with sodium acetate aqueous solution, stirred, the reaction temperature is controlled at 100~110 ℃, the reaction is 3~4h, the isopentenol acetate is obtained by stratification, the 30% sodium hydroxide solution is added to the isopentenol acetate, heated and refluxed for 3h, stratified, organic layer distillation, the fraction of 52~58 ℃/2.7 × 103Pa was collected as isopentenol with a yield of 80%. |