3858-19-3

Upstream product

• 1073-03-6 1-bromo-3-methyl-2,5-dihydro-phosphole 1-oxide 
• 71-36-3 butan-1-ol 
• 87243-93-4 1-hydroxy-3-methyl-3-phospholene 1-oxide 
• 695-59-0 2,5-dihydro-1-methoxy-3-methyl-1H-phosphole 1-oxide 
• 697-31-4 1-ethoxy-3-methyl-2,5-dihydro-1H-phosphole 1-oxide 
• 109-65-9 1-bromo-butane 

Relevant academic research and scientific papers

Synthesis of Cyclic Phosphinates by Microwave-Assisted Ionic-Liquid-Promoted Alcoholysis

A series of 1-alkoxy-3-methyl- and 3,4-dimethyl-3-phospholene 1-oxides, as well as 1-alkoxy-3-methylphospholane 1-oxides were prepared in good yields by the microwave (MW)-assisted [bmim][PF 6]-catalyzed transesterification of the corresponding methyl or ethyl esters. The alcoholyses studied represent another case, where MW irradiation has had a crucial role on the course of the reaction. The method developed is an alternative possibility to other esterifications starting from the corresponding phosphinic chlorides and acids.

Hydrolysis and alcoholysis of phosphinates and phosphonates

Phosphinic and phosphonic acids useful intermediates and biologically active compounds may be prepared from their esters: phosphinates and phosphonates, respectively, by acid-catalyzed hydrolysis either on conventional heating or on MW irradiation. The transesterification of alkyl phosphinates took place only in the presence of suitable ionic liquids as the catalysts. In the cases of phenylphosphonates, depending on the nature of the ionic liquid, the formation of the ester was accompanied by the fission of the C–O bond.

T3P-assisted esterification and amidation of phosphinic acids

A few phosphinic acids, such as phenylphosphinic acids, 1-hydroxy-3-phospholene 1-oxides and 1-hydroxyphospholane oxides are esterified with simple alcohols in the presence of propylphosphonic anhydride (T3P). If 1.1 equiv of the T3P reagent is used, the esterifications are fast and efficient at 25° C. In the case of more reactive models it was enough to apply 0.66 equiv of T3P at 85°C under microwave conditions. The amidation of 1-hydroxy-3-methyl-3-phospholene oxide could also be accomplished under similar conditions.

Direct estirification and amidation of phosphinic acids under microwave conditions

Phosphinic acids may be efficiently esterified in microwave-assisted reactions with alcohols. Especially alcohols with longer alkyl chain are suitable reagents for direct esterifications. At the same time, the direct amidation cannot be complete under such conditions. Hence, the tradional amidations via the phosphinic chloride intermediates have to be applied. The values of activation enthalpies and reaction enthalpies obtained by quantum chemical calculations justified the experimental observations. Microwave has a potential in overcoming relatively high activation enthalpies.

Esterification of five-membered cyclic phosphinic acids under mild conditions using propylphosphonic anhydride (T3P)

1-Hydroxy-phospholene 1-oxides (1 and 3) and 1-hydroxy-phospholane oxides (5 and 7) undergo fast and efficient esterification with a series of alcohols, at room temperature, in the presence of 1.1 equiv of propylphosphonic anhydride (T3P).

Microwave-assisted esterification of phosphinic acids by alcohols, phenols, and alkyl halogenides

Cyclic phosphinic acids undergo direct esterification with alcohols at ca. 200°C under microwave conditions. Copyright Taylor & Francis Group, LLC.

Alkylating esterification of 1-hydroxy-3-phospholene oxides under solventless MW conditions

1-Alkoxy-3-phospholene 1-oxides were synthesized by the alkylating esterification of the corresponding 1-hydroxy derivatives under phase transfer catalytic, microwave, and solventless conditions using alkyl halides as the reactants and potassium carbonate as the base. In the case of alkylating agents of increased reactivity, there was no need for the use ofphase transfer catalyst. Regarding the phosphinic acids, the 3- methyl-3-phospholene oxides were more reactive than the 3,4-dimethyl derivatives. Applying cesium carbonate, isomerization ofthe 3-phospholene oxide to the 2- phospholene also took place.

Novel synthesis of phosphinates by the microwave-assisted esterification of phosphinic acids

1-Hydroxy-3-phospholene oxides (1 and 3) and phenyl-H-phosphinic acid (6) are converted to the corresponding phosphinic esters (2, 4, and 7, respectively) by reaction with simple alcohols on microwave irradiation. Under traditional heating conditions, the