2681-94-9

Basic information

• Product Name: (R)-2-BROMOBUTANOIC ACID
• Synonyms: (R)-2-BROMOBUTANOIC ACID;(R)-(+)-2-BROMOBUTYRIC ACID;(R)-2-BROMOBUTYRIC ACID;D-2-Bromobutanoic acid;(2R)-2-BroMobutanoic Acid;(R)-α-BroMobutyric Acid;2-Br-butyricacid;(R)-2-ercaptobutanoic acid
• CAS NO: 2681-94-9
• Molecular Formula: C₄H₇BrO₂
• Molecular Weight: 167
• EINECS: 145-896-5
• Product Categories: API intermediates;Aliphatics;Chiral Reagents
• Mol File: 2681-94-9.mol
• Article Data: 5

Chemical Properties

• Boiling Point: 216.6 °C at 760 mmHg
• Flash Point: 84.8 °C
• Appearance: /
• Density: 1.625 g/cm³
• Storage Temp.: Refrigerator
• PKA: 2.95±0.10(Predicted)
• CAS DataBase Reference: (R)-2-BROMOBUTANOIC ACID(CAS DataBase Reference)
• NIST Chemistry Reference: (R)-2-BROMOBUTANOIC ACID(2681-94-9)
• EPA Substance Registry System: (R)-2-BROMOBUTANOIC ACID(2681-94-9)

Safety Data

• Hazardous Substances Data: 2681-94-9(Hazardous Substances Data)

Usage

Chemical Properties

Pale Yellow Oil

Upstream product

• 17642-18-1 (E)-α-bromocrotonate de methyle 
• 17642-18-1 methyl bromo-crotonate 
• 1492-24-6 L-2-aminobutyric acid 
• 10035-10-6 hydrogen bromide 
• 80-58-0 2-Bromobutyric acid 
• 3347-90-8 (2S)-2-hydroxybutanoic acid 
• 7789-69-7 phosphorus pentabromide 

Downstream Products

• 1492-24-6 L-2-aminobutyric acid 
• 1242881-37-3 (S)-2-mercaptobutanoic acid 
• 80-58-0 2-Bromobutyric acid 
• 167305-50-2 (S)-2-(Acetylthio)butanoic acid, dicyclohexylamine salt 
• 103833-72-3 (R)-2-pyrrolidone-N-butyric acid 
• 102849-49-0 (2S)-2-(2-oxopyrrolidin-1-yl)butanoic acid 
• 102152-34-1 L-2-bromobutyric acid (+)-α-methylbenzyl amide 
• 3196-15-4 methyl (R)-2-bromobutanoate 

Relevant articles and documents

Enoate reductase-mediated preparation of methyl (S)-2-bromobutanoate, a useful key intermediate for the synthesis of chiral active pharmaceutical ingredients

Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of α-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.

A synthesis of levetiracetam based on (S)-N-phenylpantolactam as a chiral auxiliary

The synthesis of levetiracetam and its enantiomer by deracemization of (±)-2-bromobutyric acid using either (S)- or (R)-N-phenylpantolactam as chiral auxiliaries, followed by SN2 substitution of the bromine atom by a 2-oxopyrrolidin-1-yl group and amidation of the carboxylic acid, is described.

Chirospecific Synthesis of (+)-Pilocarpine

An efficient chirospecific synthesis for (+)-pilocarpine (1a) using D-methionine or D-2-aminobutanol as chiral educt is described.Formation of the C3-C4 carbon bond at an early stage gave the key intermediate diethyl phosphonate.Wittig coupling of this phosphonate with 1-methyl-5-imidazolecarboxaldehyde introduced the imidazole moiety of the pilocarpine skeleton.Selective reduction of an α,β-unsaturated nitrile to the corresponding allylic alcohol, stereocontrolled hydrogenation of the olefin, and epimerization of (+)-isopilocarpine to (+)-pilocarpine via kinetic protonation led to formation of the natural alkaloid.This methodology allows chirospecific syntheses of the four possible stereoisomers of pilocarpine.A short and convenient route to (+/-)-pilocarpine based on the key intermediate phosphonate is also described.