96-23-1Relevant articles and documents
Unconventional reactivity of epichlorohydrin in the presence of triphenylphosphine: isolation of ((1,4-dioxane-2,5-diyl)-bis-(methylene))-bis-(triphenylphosphonium) chloride
Mannu, Alberto,Di Pietro, Maria Enrica,Priola, Emanuele,Baldino, Salvatore,Sacchetti, Alessandro,Mele, Andrea
, p. 1663 - 1674 (2021)
The selective formation of the heterocyclic salt ((1,4-dioxane-2,5-diyl)-bis-(methylene))-bis-(triphenylphosphonium) chloride was observed when epichlorohydrin and triphenylphosphine were reacted in CH2Cl2 at room temperature. Slow evaporation from a mixture of ethanol and ethyl acetate allows to isolate monocrystals of the heterocyclic phosphonium salt. Mechanistic investigations point to the formation of the zwitterionic intermediate 1-chloro-3-(triphenylphosphonio)-propan-2-olate, which can dimerize and generate the 1,4-dioxane derivative. In the exclusive presence of a Br?nsted acid as HCl, which usually facilitates epoxide ring opening, the exclusive formation of 1,3-dichloro-2-propanol was although observed. Also, when epichlorohydrin, PPh3, and a stoichiometric amount of HCl were mixed, (2-chloro-3-hydroxypropyl)-triphenylphosphonium chloride was formed and its isolation in pure form provides monocrystals subjectable to X-ray analysis.
Preparation method for 1,3-propylene glycol from glycerol
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Paragraph 0066-0076, (2021/04/10)
The invention relates to a preparation method for 1,3-propylene glycol from glycerol, wherein the preparation method comprises the steps of chlorohydrination reaction, cyclization reaction, hydrogenation reaction and the like. The glycerin conversion rate of the preparation method reaches 99% or above, the yield of 1,3-propylene glycol reaches 65% or above, and the preparation method has the advantages of being simple in process, mild in reaction condition, small in investment, high in technical safety and easy to operate and control.
Expeditious Syntheses to Pharmochemicals 1,3-Dihydroxyacetone, 1,3-Dichloro-, 1,3-Dibromo- And 1,3-Diiodoacetone from Glycerol 1,3-Dichlorohydrin Using Homogenous and Heterogenous Medium
Pereira, Vera Lúcia P.,da Silva, Fernanda Priscila N. R.,da Silva, Sara R. B.,dos Santos, Priscila F.
, p. 1725 - 1731 (2020/10/09)
New efficient and reproductive routes to production of 1,3-dihydroxyacetone (1), 1,3-dichloroacetone (6), 1,3-dibromoacetone (7) and 1,3-diiodoacetone (8) from glycerol 1,3-dichlorohydrin (3) were developed. The synthesis of 1 was processed in three steps from glycerol 2 (1,3-selective chlorination of 2 to 3, oxidation of 3 to 6 and subsequent di-hydroxylation) in 51% overall yield. On the other hand, 7 and 8 were produced from 3, via a trans-bromination and trans-iodination, respectively, followed by oxidation and hydroxylation steps, in 38-52% overall yield. It was used homogeneous media with different reagents (HCl/AcOH, pyridinium chlorochromate (PCC), PCC-HIO4) and heterogeneous media with reagents supported on polymer resins such as Amberlyst A26-HCrO4– form, PV-PCC (polyvinyl-pyridinium chlorochromate) and Amberlyst A26-OH– form or reagents supported on alumina such as KI/Al2O3, KBr/Al2O3, in solvent free conditions.