22801-44-1

Usage

Originator

Carboraine,Winthrop,US,1960

Manufacturing Process

Ethyl magnesium bromide is prepared in the usual way by reacting 185 parts by weight of ethyl bromide in 800 parts of anhydrous ether with 37 parts by weight of magnesium turnings. Under vigorous stirring 121 parts of 2,6- dimethyl aniline are added at a rate depending on the vigor of the gas evaporation. When the evolution of gas has ceased, 85 parts by weight of Nmethylpipecolic acid ethyl ester are added to the 2,6-dimethyl aniline magnesium bromide slurry. The mixture is refluxed for ? hour with continued stirring, after which it is cooled down. Dilute hydrochloric acid is added carefully in order to dissolve and hydrolyze the magnesium compound formed. The pH is adjusted to 5.5 and the water phase separated and extracted with additional ether in order to remove the surplus dimethyl aniline. After addition of an excess of ammonia to the solution, the reaction product, Nmethylpipecolic acid 2,6-dimethyl anilide, is recovered by extraction with isoamyl alcohol. The isoamyl alcohol solution is evaporated to dryness, the product dissolved in dilute hydrochloric acid, treated with charcoal and reprecipitated with NaOH. N-methylpipecolic acid 2,6-dimethyl anilide is obtained in crystalline form.

Therapeutic Function

Local anesthetic

Clinical Use

Mepivacaine hydrochloride [N-(2, 6-dimethylphenyl)-1-methyl 2-piperidinecarboxamide monohydrochloride] is an amino amide-type local anesthetic agent widely used to provide regional analgesia and anesthesia by local infiltration, peripheral nerve block, and epidural and caudal blocks. The pharmacological and toxicological profile of mepivacaine is quite similar to that of lidocaine, except that mepivacaine has a slightly longer duration of action and lacks the vasodilator activity of lidocaine. For this reason, it serves as an alternate choice for lidocaine when addition of epinephrine is not recommended in patients with hypertensive vascular disease.

Synthesis

Mepivacaine is N-(2,6-dimethylphenyl)-1-methyl-2-piperindincarboxamide (2.2.3). Two primary methods of synthesis have been suggested. According to the first, mepivacaine is synthesized by reacting the ethyl ester of 1-methylpiperindine-2-carboxylic acid with 2,6-dimethylanilinomagnesium bromide, which is synthesized from 2,6- dimethylaniline and ethylmagnesium bromide [12–14]. According to the figure below, reacting 2,6-dimethylaniline with the acid chloride of pyridine-carboxylic acid first gives the 2,6-xylidide of α-picolinic acid (2.2.4). Then the aromatic pyridine ring is reduced to piperidine by hydrogen in the presence of a platinum on carbon catalyst. The resulting 2,6-xylidide α-pipecolinic acid (2.2.5) is methylated to mepivacaine using formaldehyde with simultaneous reduction by hydrogen in the presence of platinum on carbon catalyst [15].

Metabolism

Mepivacaine undergoes extensive hepatic metabolism catalyzed by CYP1A2, with only a small percentage of the administered dosage (<10%) being excreted unchanged in the urine. The major metabolic biotransformations of mepivacaine are N-dealkylation (to give the N-demethylated compound 2′,6′-pipecoloxylidide) and aromatic hydroxylations. These metabolites are excreted as their corresponding glucuronides.

InChI:InChI=1/C15H22N2O/c1-11-7-6-8-12(2)14(11)16-15(18)13-9-4-5-10-17(13)3/h6-8,13H,4-5,9-10H2,1-3H3,(H,16,18)

Upstream product

• 77-78-1 dimethyl sulfate 
• 626-67-5 N-methylcyclohexylamine 
• 40397-98-6 2,5-dimethylphenyl isocyanate 
• 39627-98-0 2-pyridine-carboxamide-N-(2,6-dimethylphenyl) 
• 98-98-6 2-Picolinic acid 
• 67-56-1 methanol 
• 87-62-7 2,6-dimethylaniline 
• 50-00-0 formaldehyd 
• 27262-40-4 (S)-2',6'-pipecoloxylidide 
• 74-88-4 methyl iodide 
• 98626-58-5 L-pipecolic acid chloride hydrochloride 
• 3105-95-1 pipecolinic acid 
• 111562-44-8 2-(2,6-dimethyl-phenylcarbamoyl)-1-methyl-pyridinium; iodide 

Relevant academic research and scientific papers

A convenient and highly enantioselective synthesis of (S)-2-pipecolic acid: an efficient access to caine anesthetics

A novel and enantioselective synthesis of (S)-2-pipecolic acid (5) has been achieved from Oppolzer’s sultam (1) and ethyl N-(diphenylmethylene)glycinate (2) as readily available starting materials. The highly stereoselective alkylation of chiral glycine intermediate (3) with 1,4-dibromobutane afforded the key backbone of (S)-2-pipecolic acid (5) in one-step that was utilized into the preparation of the local anesthetics mepivacaine, ropivacaine and bupivacaine.

Synthesis of Mepivacaine and Its Analogues by a Continuous-Flow Tandem Hydrogenation/Reductive Amination Strategy

Herein we report a convenient, fast, and high-yielding method for the generation of the racemic amide anaesthetics mepivacaine, ropivacaine, and bupivacaine. Coupling of α-picolinic acid and 2,6-xylidine under sealed-vessel microwave conditions generates the intermediate amide after a reaction time of only 5 min at 150 °C. Subsequent reaction in a continuous-flow high-pressure hydrogenator (H-Cube ProTM) in the presence of the respective aldehyde directly converts the intermediate to the final amide anaesthetics in a continuous, integrated, multi-step ring-hydrogenation/reductive amination protocol. Merits and limitations of the protocol are discussed.

PROCESS FOR THE PREPARATION OF (S)-1-ALKYL-2',6'-PIPECOLOXYLIDIDE COMPOUND

The present invention relates to an improved process for the preparation of high chiral purity (S)-1-alkyl-2',6'-Pipecoloxylidide compound such as Ropivacaine, Levobupivacaine or salts thereof, which comprises crystallization of (S)-1-alkyl-2',6'- Pipecoloxylidide acid addition salt in a non-alcoholic and non-ketonic solvent.

Enantioselective total syntheses of ropivacaine and its analogues

An alternative asymmetric synthesis of ropivacaine and analogues employing the 'cation pool' strategy and host/guest supramolecular co-catalysis approach is presented. In this study, chiral auxiliaries, several soft nucleophiles as well as one-pot conditions for anodic oxidation, followed by nucleophilic addition, have been applied.

Radical fixation of functionalized carbon resources: α-sp 3C - H carbamoylation of tertiary amines with aryl isocyanates

A new carbamoylation of tertiary amines is reported. This rare C - H transformation features the direct generation of α-aminoalkyl radicals from tertiary amines, followed by the addition of the resultant nucleophilic radicals to isocyanates, enabling unique access to N,N-dialkylated amino acid derivatives. The authors put forward a mechanistic proposal that is based on the isolation of borinamides produced by capturing nitrogen radical intermediates with Et3B. The present transformation provides a novel one-step process for producing mepivacaine, a clinically important local anesthetic, from readily available materials.

Local anaesthetic salts of chondroitinsulfate compounds

Water-soluble local anaesthetic compounds having sustained effect are prepared by reacting a chondroitin derivative with a basic local anaesthetic compound.