2,6-Di-tert-butyl-4-methylpyridine Property

Melting point:

33-36 °C (lit.)

Boiling point:

233 °C (lit.)

Density 

1,476 g/cm³

refractive index 

n20/D 1.4763(lit.)

Flash point:

183 °F

storage temp. 

2-8°C

solubility 

ethanol: soluble5%, clear to slightly hazy, colorless to dark yellow

form 

Liquid or Low Melting Solid

pka

6.88±0.10(Predicted)

color 

brown

Water Solubility 

Sparingly soluble in water. Soluble in ethanol, acetic acid and diethyl ether.

Sensitive 

Air & Light Sensitive

BRN 

130503

InChIKey

HVHZEKKZMFRULH-UHFFFAOYSA-N

CAS DataBase Reference

38222-83-2(CAS DataBase Reference)

Safety

Hazard Codes 

Xn,Xi

Risk Statements 

22-36/37/38

Safety Statements 

26-37/39

WGK Germany 

3

F 

8-10-23

HS Code 

29333990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

2,6-Di-tert-butyl-4-methylpyridine Chemical Properties,Usage,Production

Chemical Properties

light yellow powder

Uses

2,6-Di-tert-butyl-4-methylpyridine is used for the generation of enol triflates from ketones using trifluoromethanesulfonic anhydride. It is also used in the synthesis of 1,2-dihydro-2-silanaphthalene derivatives, as base in PtCl4-catalyzed cyclization reactions of homopropargyl azide derivatives and in diastereoselective synthesis of β-thiomannopyranosides.

Uses

2,6-Di-tert-butyl-4-methylpyridine has been used:

• in the synthesis of 1,2-dihydro-2-silanaphthalene derivatives
• as base in PtCl₄-catalyzed cyclization reactions of homopropargyl azide derivatives
• diastereoselective synthesis of β-thiomannopyranosides

Synthesis Reference(s)

The Journal of Organic Chemistry, 41, p. 3034, 1976 DOI: 10.1021/jo00880a027

General Description

2,6-Di-tert-butyl-4-methylpyridine is a sterically hindered, non-nucleophilic base which distinguishes between protonic and Lewis acids. It also enables the direct high-yield conversion of aldehydes and ketones to vinyl triflates. It inhibits desilylation and hydration of the products during GaCl₃-catalyzed ortho-ethynylation of phenol.

Purification Methods

A possible impurity is 2,6-di-tert-butyl-4-neopentylpyridine. Attempts to remove coloured impurities directly by distillation, acid-base extraction or treatment with activated charcoal were unsuccessful. Pure material is obtained by dissolving 0.3mole of the alkylpyridine in pentane (150mL) and introducing it at the top of a cold water jacketed chromatographic column (40 x 4.5cm) (cooling is necessary because the base in pentane reacts exothermically with alumina) containing activated and acidic alumina (300g). The column is eluted with pentane using a 1L constant pressure funnel fitted at the top of the column to provide slight pressure. All the pyridine is obtained in the first two litres of eluent (the progress of elution is monitored by spotting a fluorescent TLC plate and examining under short wave UV light—a dark blue spot is evidence for the presence of the alkylpyridine). Elution is complete in 1hour. Pentane is removed on a rotovap with 90-93% recovery yielding a liquid which solidifies on cooling, m 31-32o, and the base can be distilled. The HPtCl6 salt has m 213-314o(dec), and the CF3SO3H salt has m 202.5-203.5o (from CH2Cl2). [Anderson & Stang Org Synth Coll Vol VII 144 1981, Beilstein 20/6 V 190.]