1-Chloro-3-methyl-2-butene

Colorless Liquid

1-Chloro-3-methyl-2-butene is a reactive allylic chloride that is used as an alkylating agent in synthetic chemistry. 1-Chloro-3-methyl-2-butene is also used as a reagent to synthesize Hyperforin, an antibiotic originating from St. John’s wort that has the ability to inhibit growth of tumour cells.

The preparation method is to react isoprene with concentrated hydrochloric acid in the presence of catalyst CuCl, or pass hydrogen chloride into isoprene to obtain 1-chloro-3-methylbutene-2 and 3-chloro-3- A mixture of methylbutene-1, the latter can be transposed at room temperature to obtain 1-chloro-3-methylbutene-2. The reaction equation is shown in the figure: Add CuCl as a catalyst to the concentrated hydrochloric acid solution, and stir vigorously to dissolve it, then control the temperature below 20°C, add isoprene dropwise, maintain 20°C after the dropwise addition, and continue stirring 0.5h, the reaction is over, the organic layer is quickly separated, neutralized and dried with anhydrous Na2CO3, unreacted isoprene and low boilers generated by side reactions are evaporated under normal pressure, and then vacuum distillation collects 79℃/40 The kPa fraction is the product (chloroisoprene bp105～115℃). Hydrogen chloride can also be used to pass into isoprene, the reaction temperature is 0-10℃, the temperature of hydrogen chloride is -5℃, the content of isoprene in the reaction solution is controlled by gas chromatography to determine the end of the reaction, and the transposition is stirred at room temperature For about 4h.

Used as intermediate for pesticides, medicines and spices

Molecular Weight:104.58
XLogP3:2.3
Rotatable Bond Count:1
Exact Mass:104.0392780
Monoisotopic Mass:104.0392780
Heavy Atom Count:6
Complexity:51
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes