99-66-1 Usage
Uses
Used in Pharmaceutical Industry:
2-Propylpentanoic acid is used as an antiepileptic drug for the treatment and management of seizure disorders, mania, and prophylactic treatment of migraine headaches. In epileptics, valproic acid is used to control absence seizures, tonic-clonic seizures (grand mal), complex partial seizures, and the seizures associated with various conditions.
Used in Research Applications:
2-Propylpentanoic acid is used as a supplement in mouse embryonic fibroblast-conditioned medium (MEF-CM) to feed the cells, aiding in various research studies and experiments.
Used in Drug Metabolism:
2-Propylpentanoic acid is an important inhibitor of the cytochrome P450 isozymes, mainly of CYP2C9 and also of uridine diphosphate (UDP)-glucuronyl transferase and epoxide hydrolase, playing a role in drug metabolism and interactions.
Brand Names:
Depakene (Abbott), Valproine, Vederon, Epilim (Sanofi, Paris), Episenta (Desitin, Hamburg), and Depakote (Sanofi, Paris).
Generic formulation
MHRA/ CHM advice to minimize risk when switching patients with epilepsy between different manufacturers’ products (including generic products):
The need for continued supply of a particular manufacturer’s product should be based on clinical judgment and consultation with the patient and/ or carer, taking into account factors such as seizure frequency and treatment history.
Indications
Epilepsy
Monotherapy and adjunctive therapy of focal and generalized seizures.
Recommendations summarized from NICE (2012)
Seizure types: first line (generalized tonic- clonic seizures, tonic/ atonic seizures, absence seizures, myoclonic seizures, focal seizures), adjunctive (generalized tonic- clonic seizures, absence seizures, myoclonic seizures, focal seizures).
Epilepsy types: first line (absence syndromes, juvenile myoclonic epilepsy, epilepsy with generalized tonic- clonic seizures only, idiopathic generalized epilepsy, benign epilepsy with centrotemporal spikes, Panayiotopoulos syndrome, late- onset childhood occipital epilepsy, Dravet syndrome, Lennox– Gastaut syndrome), adjunctive (absence syndromes, juvenile myoclonic epilepsy, epilepsy with generalized tonic- clonic seizures only, idiopathic generalized epilepsy, benign epilepsy with centrotemporal spikes, panayiotopoulos syndrome, late- onset childhood occipital epilepsy).
Psychiatry
Treatment of acute mania associated with bipolar disorder.
Neurology
Migraine prophylaxis (unlicensed).
Dose titration
Epilepsy
600 mg daily divided into 1 or 2 doses, then increased by 150– 300 mg every 3 days; usual maintenance 1000– 2000 mg (or 20–30 mg/ kg) daily divided into 1 or 2 doses (max 2500 mg daily).
Mania
750 mg daily divided into 1 or 2 doses, adjusted according to response; usual maintenance 000– 2000 mg daily divided into 1 or 2 doses (doses greater than 45 mg/ kg daily require careful monitoring).
Plasma levels monitoring
Although plasma levels can be measured, and a therapeutic range has been postulated (40– 100 mg/ L), plasma valproate concentrations are not a useful index of efficacy. Therefore, routine monitoring is unhelpful.
Cautions
Patients with systemic lupus erythematosus.
Patients with a personal or family history of severe hepatic dysfunction (contraindication).
Patients with known metabolic disorders (contraindication).
? Patients with suspected metabolic disorders (contraindication).
? Patients with porphyria (contraindication).
Adverse effects
Valproate can be associated with adverse effects at the level the nervous system and other systems.
Interactions
With AEDs
AEDs with enzyme inducing effect (including carbamazepine, phenobarbital, phenytoin) decrease valproate plasma concentrations.
Valproate reduces the metabolism of lamotrigine and increases the lamotrigine mean half- life by nearly two fold. This interaction may lead to increased lamotrigine toxicity, in particular serious skin rashes.
Valproate increases phenobarbital and primidone plasma concentrations with exacerbation of its adverse effects (sedation may occur).
Valproate may potentiate toxic effects of carbamazepine.
Valproate decreases phenytoin total plasma concentration, but displaces phenytoin from its plasma protein binding sites and reduces its hepatic catabolism, thereby increasing phenytoin free form with possible overdose symptoms.
Concomitant administration of valproate and topiramate has been associated with encephalopathy and/ or hyperammonaemia. In patients taking these two AEDs, careful monitoring of signs and symptoms is advised (especially in patients with pre- existing encephalopathy).
With other drugs
Mefloquine and chloroquine increase valproate metabolism and may lower the seizure threshold (therefore, epileptic seizures may occur in cases of combined therapy).
Decreases in blood levels of valproate have been reported when it is coadministered with carbapenem antibiotics (such as imipenem, panipenem, meropenem), resulting in a 60– 00% decrease in valproate levels within 2 days, sometimes associated with convulsions.
Colestyramine may decrease the absorption of valproate.
Rifampicin may decrease valproate blood levels, resulting in a lack of therapeutic effect.
In case of concomitant use of valproate and highly protein bound agents (e.g. aspirin), free valproate plasma levels may be increased.
Valproic acid plasma levels may be increased (as a result of reduced hepatic metabolism) in case of concomitant use with cimetidine or erythromycin.
Valproate may potentiate the effect of other psychotropics such as antipsychotics (especially olanzapine), MAO inhibitors, antidepressants, and benzodiazepines.
Valproate may raise zidovudine plasma concentration, possibly leading to increased zidovudine toxicity.
The anticoagulant effect of warfarin and other coumarin anticoagulants may be increased following displacement from plasma protein binding sites by valproate.
With alcohol/food
There are no specific foods that must be excluded from diet when taking valproate. Alcohol intake is not recommended during treatment with valproate.
Special populations
Hepatic impairment
Avoid if possible: hepatotoxicity and hepatic failure may occasionally occur (usually in first 6 months). Avoid in active liver disease.
Renal impairment
In patients with renal insufficiency, it may be necessary to decrease dosage of valproate. As monitoring of plasma concentrations may be misleading, dosage should be adjusted according to clinical monitoring.
Pregnancy
Valproate is associated with the highest risk of major and minor congenital malformations (in particular neural tube defects) and neurodevelopmental effects among AEDs.
Therefore, valproate should not be used during pregnancy or in women of child- bearing age unless there is no safer alternative and only after a careful discussion of the risks.
If valproate is to be used during pregnancy, the lowest effective dose should be prescribed in divided doses or as modified- release tablets to avoid peaks in plasma valproate concentrations (doses greater than 000 mg daily are associated with an increased risk of teratogenicity). The dose should be monitored carefully during pregnancy and after birth, and adjustments made on a clinical basis.
Avoid use in the treatment of epilepsy and bipolar disorder unless there is no safer alternative and only after a careful discussion of the risks (effective contraception advised in women of child- bearing potential).
Neonatal bleeding (related to hypofibrinaemia) and hepatotoxicity have been reported, and specialist prenatal monitoring should be instigated when valproate has been taken in pregnancy.
Valproate is excreted in human milk with a concentration ranging from 1 to 10% of maternal serum levels. Haematological disorders have been shown in breastfed newborns/ infants of treated women. A decision must be made whether to discontinue breastfeeding or to discontinue/ abstain from valproate therapy, taking into account the benefit of breastfeeding for the child and the benefit of therapy for the woman.
Behavioural and cognitive effects in patients with epilepsy
The incidence of adverse psychiatric effects associated with valproate in patients with epilepsy is overall negligible (apart from reports of depression, irritability, and other behavioural symptoms in the context of encephalopathy). Cognitive difficulties have occasionally been reported in patients with epilepsy treated with valproate, especially affecting attention and memory functions.
Psychiatric use
Valproate is an effective mood stabilizer, licensed for the treatment of acute mania in patients with bipolar disorder. Although it has no formal indication, it is also considered a first- line agent for maintenance treatment in bipolar disorder. There is evidence suggesting efficacy of valproate in the treatment of hostility among patients with acute alcohol- associated hallucinosis or schizophrenia, and in impulsive/ aggressive behaviours, either in isolation or in the context of comorbid bipolar disorder or personality disorder. Available data show a limited efficacy of valproate in depressive disorders, schizophrenia, pathological gambling, as well as benzodiazepine/ cannabis/ cocaine dependence and acute alcohol withdrawal.
Therapeutic Function
Anticonvulsant
Biological Functions
Although it is marketed as both valproic acid
(Depakene) and as sodium valproate (Depakote), it is
the valproate ion that is absorbed from the gastrointestinal
tract and is the active form.
As with several other AEDs, it is difficult to ascribe
a single mechanism of action to valproic acid.This compound
has broad anticonvulsant activity, both in experimental
studies and in the therapeutic management of
human epilepsy.Valproic acid has been shown to block
voltage-dependent sodium channels at therapeutically
relevant concentrations. In several experimental studies,
valproate caused an increase in brain GABA; the
mechanism was unclear.There is evidence that valproate may also inhibit T-calcium channels and that this may
be important in its mechanism of action in patients with
absence epilepsy.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
2-Propylpentanoic acid is a carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in 2-Propylpentanoic acid to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions. 2-Propylpentanoic acid is incompatible with bases, oxidizing agents and reducing agents. 2-Propylpentanoic acid is corrosive. .
Fire Hazard
2-Propylpentanoic acid is combustible.
Biochem/physiol Actions
Anticonvulsant that also has efficacy as a mood stabilizer in bipolar disorder
Mechanism of action
Although its mechanism of action is not clearly established, valproate appears to increase the inhibitory effect of GABA,
possibly by activation of glutamic acid decarboxylase or inhibition of GABA-transaminase). The high drug
concentrations required, however, cast doubt on the clinical relevance of this effect. Furthermore, valproate recently has been
shown to decrease the uptake of GABA into cultured astrocytes; this action may contribute to the AED efficacy. Valproate
is known to produce a blockade of high-frequency repetitive firing by slowing the rate of Na+
recovery from inactivation, a
mechanism consistent with the actions of phenytoin and CBZ. Valproate blocks the low-threshold T-type Ca2+ channel.
Consequently, the overall therapeutic utility of valproate is likely caused by multiple effects.
Valproate is indicated for initial or adjunct treatment of absence seizures or as an adjunct when absence seizures occur in
combination with either tonic-clonic seizures, myoclonic seizures, or both. For patients with unambiguous idiopathic generalized
epilepsy, valproate often is the drug of choice, because it controls absence, myoclonic, and generalized tonic-clonic seizures
well. It also is approved by U.S. FDA for use in complex partial seizures, occurring with or without other seizure types in
adults or children 10 years of age or older. In new patients with typical absence seizures, ethosuximide is preferred to
valproate because of the latter drug's risk of producing hepatotoxicity. In a comparative trial, sodium valproate and
ethosuximide were equally effective when either drug was given alone or in combination with other AEDs in children with typical
absence seizures. In atypical absence seizures (Lennox-Gastaut syndrome), sodium valproate is more effective, whereas in
myoclonic seizures, it is less effective than clonazepam. Valproate is approved by the U.S. FDA for use in bipolar disorder and
against migraine headaches.
Pharmacokinetics
Valproate undergoes rapid and complete absorption, which is only slightly slowed by food. It is 90% protein bound, and its
clearance is dose-dependent because of an increase in the free fraction of the drug at higher doses. It is metabolized almost
entirely by the liver, with 30 to 50% of an orally administered dose being eliminated in the urine as its acyl glucuronide
conjugate, 40% from mitochondrial β-oxidation, approximately 15 to 20% by ω-oxidation, and less than 3% is excreted
unchanged in urine. Its major active metabolite is (E)-2-ene valproate (trans 2-ene valproate). Its 4-ene metabolite has been
proposed to be a reactive metabolite responsible for the hepatotoxicity of valproate. Other metabolites found
in the urine include 3-oxo- and 4-hydroxyvalproate. The elimination half-life for valproate ranged from 9 to 16 hours following
oral dosing regimens of 250 to 1,000 mg. Patients who are not taking enzyme-inducing AEDs (carbamazepine, phenytoin, and
phenobarbital) will clear valproate more rapidly; therefore, monitoring of AED plasma concentrations should be intensified
whenever concurrent AEDs are introduced or withdrawn.
Clinical Use
Valproic acid is well absorbed from the gastrointestinal
tract and is highly bound (~90%) to plasma protein,
and most of the compound is therefore retained
within the vascular compartment.Valproate rapidly enters
the brain from the circulation; the subsequent decline
in brain concentration parallels that in plasma, indicating
equilibration between brain and capillary
blood. A large number of metabolites have been identified,
but it is not known whether they play a role in the
anticonvulsant effect of the parent drug. Valproic acid
inhibits the metabolism of several drugs, including phenobarbital,
primidone, carbamazepine, and phenytoin,
leading to an increased blood level of these compounds.
At high doses, valproic acid can inhibit its own metabolism.
It can also displace phenytoin from binding sites
on plasma proteins, with a resultant increase in unbound
phenytoin and increased phenytoin toxicity. In
this instance, the dosage of phenytoin should be adjusted
as required. These examples reinforce the need
to determine serum anticonvulsant levels in epileptic
patients when polytherapy is employed.
Valproic acid has become a major AED against several
seizure types. It is highly effective against absence
seizures and myoclonic seizures. In addition, valproic
acid can be used either alone or in combination with
other drugs for the treatment of generalized tonic–
clonic epilepsy and for partial seizures with complex
symptoms.
Side effects
The most serious adverse effect associated with valproic
acid is fatal hepatic failure. Fatal hepatotoxicity is
most likely to occur in children under age 2 years, especially
in those with severe seizures who are given multiple
anticonvulsant drug therapy. The hepatotoxicity is
not dose related and is considered an idiosyncratic reaction;
it can occur in individuals in other age groups,
and therefore, valproic acid should not be administered
to patients with hepatic disease or significant hepatic
dysfunction or to those who are hypersensitive to it.
Valproic acid administration has been linked to an increased
incidence of neural tube defects in the fetus of
mothers who received valproate during the first
trimester of pregnancy. Patients taking valproate may
develop clotting abnormalities.
Valproic acid causes hair loss in about 5% of patients,
but this effect is reversible. Transient gastrointestinal
effects are common, and some mild behavioral
effects have been reported. Metabolic effects, including
hyperglycemia, hyperglycinuria, and hyperammonemia,
have been reported. An increase in body weight also
has been noted. Valproic acid is not a CNS depressant,
but its administration may lead to increased depression
if it is used in combination with phenobarbital, primidone,
benzodiazepines, or other CNS depressant agents.
Synthesis
Valproic acid, 2-propylvaleric acid (9.4.3), is synthesized by the alkylation of cyanoacetic
ester with two moles of propylbromide, to give dipropylcyanoacetic ester (9.4.1).
Hydrolysis and decarboxylation of the carbethyoxy group gives dipropylacetonitrile
(9.4.2), which is hydrolyzed into valproic acid (9.4.3) [12–15].
references
[1] phiel c j, zhang f, huang e y, et al. histone deacetylase is a direct target of valproic acid, a potent anticonvulsant, mood stabilizer, and teratogen. journal of biological chemistry, 2001, 276(39): 36734-36741.[2] chateauvieux s, morceau f, dicato m, et al. molecular and therapeutic potential and toxicity of valproic acid. biomed research international, 2010, 2010.
Check Digit Verification of cas no
The CAS Registry Mumber 99-66-1 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 9 and 9 respectively; the second part has 2 digits, 6 and 6 respectively.
Calculate Digit Verification of CAS Registry Number 99-66:
(4*9)+(3*9)+(2*6)+(1*6)=81
81 % 10 = 1
So 99-66-1 is a valid CAS Registry Number.
InChI:InChI=1/C26H28Cl2N4O4.C8H16O2/c1-19(33)31-10-12-32(13-11-31)21-3-5-22(6-4-21)34-15-23-16-35-26(36-23,17-30-9-8-29-18-30)24-7-2-20(27)14-25(24)28;1-3-5-7(6-4-2)8(9)10/h2-9,14,18,23H,10-13,15-17H2,1H3;7H,3-6H2,1-2H3,(H,9,10)/t23-,26-;/m0./s1
99-66-1Relevant articles and documents
23Na magic-angle spinning and double-rotation NMR study of solid forms of sodium valproate
Dicaire, Nuiok M.,Perras, Frederic A.,Bryce, David L.
, p. 9 - 15 (2014)
Sodium valproate is a pharmaceutical with applications in the treatment of epilepsy, bipolar disorder, and other ailments. Sodium valproate can exist in many hydrated and acid-stabilized forms in the solid state, and it can be difficult to obtain precise structural information about many of these. Here, we present a 13C and 23Na solid-state NMR study of several forms of sodium valproate, only one of which has been previously structurally characterized by single-crystal X-ray diffraction. 23Na magic-angle spinning (MAS), double-rotation (DOR), and multiple-quantum magic-angle spinning (MQMAS) NMR spectra are shown to provide useful information on the number of molecules in the asymmetric unit, the local coordination geometry of the sodium cations, and the presence of amorphous phases. Two previously identified forms are shown to be highly similar, or identical, according to the 23Na NMR data. The utility of carrying out both DOR and MQMAS NMR experiments to identify all crystallographically unique sites is demonstrated. 13C cross-polarization MAS NMR spectra also provide complementary information on the number of molecules in the asymmetric unit and the crystallinity of the sample.
Michael reaction of nitroalkanes with β-nitroacrylates under a solid promoter: Advanced regio-and diastereoselective synthesis of nitro-functionalized ββ-unsaturated esters and 1,3-butadiene-2-carboxylates
Palmieri, Alessandro,Gabrielli, Serena,Ballini, Roberto
, p. 1485 - 1492 (2010)
A new class of nitro-functionalized α,β-unsaturated esters has been prepared by a regio-and diastereoselective Michael addition of nitroalkanes to βnitroacrylates, performed at room temperature, under carbonate on polymer as promoter, and in the presence
Novel method for preparing valproic acid
-
Paragraph 0018; 0027-0051, (2021/08/06)
The invention discloses a novel method for preparing valproic acid. According to the novel method, the valproic acid is prepared by taking 2-cyano-2-propyl valeric acid as a starting material through a one-pot method. According to the method disclosed by the invention, the valproic acid is prepared at 120-160 DEG C by taking the 2-cyano-2-propyl valeric acid as a raw material and the sulfuric acid aqueous solution as a catalyst, the reaction yield can reach 80%, and the purity of the valproic acid product can reach 99%; the preparation process is simple, the steps are short, and the manpower and equipment cost input for intermediate center control and preparation in the industry is greatly reduced. According to the method disclosed by the invention, a sulfuric acid hydrolysis mechanism of 2-cyano-2-propyl valeric acid is adopted, and compared with a traditional mechanism that amide is oxidized into carboxylic acid by nitrous acid, the situation that sodium nitrite is converted into nitrous acid in an acid environment and the nitrous acid is further converted into nitric oxide and nitrogen dioxide gas under an acid condition to pollute atmosphere and water is avoided; meanwhile, the operation safety of operators is improved, and corrosion of nitric oxide and nitrogen dioxide to equipment is avoided.
Preparation method of sodium valproate
-
Paragraph 0044-0049; 0052-0057; 0060-0065; 0068-0073; ..., (2021/08/06)
The invention discloses a preparation method of sodium valproate, which comprises the following steps of by taking 2-cyano-2-propyl valerate as a raw material and a sulfuric acid aqueous solution as a catalyst, obtaining a mixture of valproic acid and valproate at 120-160 DEG C, then hydrolyzing by using an alkali solution to obtain a valproate aqueous solution, and extracting, acidifying and rectifying to obtain valproic acid. The reaction yield can reach 76%, and the purity of valproic acid can reach 99%. Compared with the traditional mechanism of oxidizing amide into carboxylic acid by nitrous acid, the method provided by the invention avoids the pollution to the atmosphere and the water body caused by the conversion of sodium nitrite into nitrous acid in an acid environment and the further conversion of nitrous acid into nitric oxide and nitrogen dioxide gas under an acid condition, and improves the operation safety of operators at the same time; and corrosion of nitric oxide and nitrogen dioxide to equipment is avoided.
Achiral Derivatives of Hydroxamate AR-42 Potently Inhibit Class i HDAC Enzymes and Cancer Cell Proliferation
Tng, Jiahui,Lim, Junxian,Wu, Kai-Chen,Lucke, Andrew J.,Xu, Weijun,Reid, Robert C.,Fairlie, David P.
supporting information, p. 5956 - 5971 (2020/06/05)
AR-42 is an orally active inhibitor of histone deacetylases (HDACs) in clinical trials for multiple myeloma, leukemia, and lymphoma. It has few hydrogen bond donors and acceptors but is a chiral 2-arylbutyrate and potentially prone to racemization. We report achiral AR-42 analogues incorporating a cycloalkyl group linked via a quaternary carbon atom, with up to 40-fold increased potency against human class I HDACs (e.g., JT86, IC50 0.7 nM, HDAC1), 25-fold increased cytotoxicity against five human cancer cell lines, and up to 70-fold less toxicity in normal human cells. JT86 was ninefold more potent than racAR-42 in promoting accumulation of acetylated histone H4 in MM96L melanoma cells. Molecular modeling and structure-activity relationships support binding to HDAC1 with tetrahydropyran acting as a hydrophobic shield from water at the enzyme surface. Such potent inhibitors of class I HDACs may show benefits in diseases (cancers, parasitic infections, inflammatory conditions) where AR-42 is active.
Preparation method and application of Grignard reagent
-
Paragraph 0053; 0056; 0057, (2020/12/29)
The invention relates to a preparation method and application of a Grignard reagent, the Grignard reagent is obtained by treating a halide with a structural formula as a raw material with magnesium inan organic solvent, X is a halogen atom and is selected from Cl, Br and I, R2 is an alkyl or aryl group containing 2-9 carbon atoms. The Grignard reagent is mainly applied to a synthetic process of dimopidol and hydrochloride thereof, and is used for introducing an alkyl side chain. The whole synthetic process of dimopidol and hydrochloride thereof is safe and efficient, each step of reaction operation is simple and safe, and the reaction yield is high so that industrial production can be realized.
Method for recovering 2-propylmalonic acid and preparing valproic acid from 2-propylmalonic acid
-
Paragraph 0015-0030, (2021/01/15)
The invention discloses a method for recovering 2-propylmalonic acid and preparing valproic acid from 2-propylmalonic acid, and the method for recovering 2-propylmalonic acid and preparing valproic acid from 2-propylmalonic acid includes the following steps: (1) collecting acid water after centrifuging dipropylmalonic acid, adding ether, ester, chlorinated hydrocarbon and an alcohol (immiscible with water) solvent, stirring, extracting, layering, and drying to obtain dipropylmalonic acid with the recovery rate of more than 90%; and (2) performing esterification, propylation, hydrolysis and acidification on the 2-propylmalonic acid to obtain dipropylmalonic acid, and performing decarboxylation to obtain high-purity valproic acid (the content is greater than or equal to 99.5%). Through recovery and comprehensive utilization of the 2-propylmalonic acid, the production cost of the 2-propylvaleric acid is reduced, and the pressure of subsequent environmental protection treatment is greatlyreduced.
Synthesis of Acyclic Aliphatic Amides with Contiguous Stereogenic Centers via Palladium-Catalyzed Enantio-, Chemo- and Diastereoselective Methylene C(sp3)?H arylation
Deng, Yao-Ting,Ding, Yi,Han, Ye-Qiang,Kong, Ke-Xin,Shi, Bing-Feng,Wu, Le-Song,Yang, Xu
supporting information, p. 20455 - 20458 (2020/09/07)
The enantioselective desymmetrizing C?H activation of α-gem-dialkyl acyclic amides remains challenging because the availability of four chemically identical unbiased methylene C(sp3)?H bonds and increased rotational freedoms of the acyclic systems add tremendous difficulties for chemo- and stereocontrol. We have developed a method for the synthesis of acyclic aliphatic amides with α,β-contiguous stereogenic centers via PdII-catalyzed asymmetric arylation of unbiased methylene C(sp3)?H, in good yields and with high levels of enantio-, chemo- and diastereoselectivity (up to >99 % ee and >20:1 d.r.). Successive application of this method enables the sequential arylation of the gem-dialkyl groups with two different aryl iodides, giving a range of β-Ar1-β′-Ar2-aliphatic acyclic amides containing three contiguous stereogenic centers with excellent diastereoselectivity.
Derivatization of valproic acid using ferrocene derivatives: Synthesis, characterization and investigation of optical and electrochemical properties
Rahimpour, Keshvar,Jouyban, Abolghasem,Teimuri-Mofrad, Reza
, (2019/07/03)
New ferrocenyl-based valproic acid (VPA) ester derivatives were designed and synthesized according to the reaction of appropriate haloalkylferrocene derivatives with VPA in the presence of K2CO3 and a catalytic amount of 18-crown-6 ether. Elemental analyses and Fourier transform infrared, 1H NMR, 13C NMR and mass spectra all well confirmed the predicted molecular structure. This is the first report in which ferrocene has been applied in derivatization of VPA as a chromogenic group. The electrochemical properties of the synthesized compounds were studied using cyclic voltammetry measurements, and energies of the frontier molecular orbitals were determined. In addition, the solubilities of the final compounds were studied in distilled water, phosphate buffer (pH?=?7.4) and 0.9% (w/v) NaCl solution.
NCP ligand, [...] complex, synthesis method, intermediate and application
-
Paragraph 0122; 0214-02176, (2018/07/30)
The invention discloses an NCP ligand, iridium complex, synthetic method, intermediate and application thereof. The invention provides an NCP ligand and an NCP ligand iridium complex, wherein R1, R2, R3, R4, R5, R6 and R7 separately represent hydrogen atom or C1-C30 alkyl, R' and R'' independently represent C1-C30 alkyl. The invention provides the application of the NCP ligand iridium complex to the catalysis of alkane dehydrogenation reaction, olefin isomerization reaction, alcohol dehydrogenation reaction, ester alpha alkylation reaction, and amide alpha alkylation reaction. The NCP ligand provided by the invention contains dialkyl substituted phosphine, which has strong electron donating ability and can form a NCP ligand iridium complex by complexing with iridium. The NCP ligand iridium complex uses pyridine to replace a conventional alkyl phosphate electron donor, and has the advantages of good stability, high selectivity on alkane dehydrogenation reaction, mild reaction conditions, good catalytic effect, and industrial production prospect.
