Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and 2,6-Lutidine: Difference between pages

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 477212168

| Reference = <ref name="M">{{Merck11th|5485}}</ref>

| PIN = 2,6-Dimethylpyridine

|Section1={{Chembox Identifiers

| ChemSpiderID = 13842613

| EINECS = 203-587-3

| StdInChI=1S/C7H9N/c1-6-4-3-5-7(2)8-6/h3-5H,1-2H3

| StdInChIKey = OISVCGZHLKNMSJ-UHFFFAOYSA-N

| UNNumber = 2734

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 32548

| Beilstein = 105690

| Gmelin = 2863

}}

|Section2={{Chembox Properties

| Appearance = colorless oily liquid

| MeltingPt_notes =

| BoilingPt_notes =

| Solubility = 27.2% at 45.3&nbsp;°C

| pKa = 6.72<ref name=Ullmann/>

| pKb =

| MagSus = {{val|-71.72e-6|u=cm³/mol}}}}

|Section7={{Chembox Hazards

| NFPA-H = 2

| NFPA-F = 3

| NFPA-R = 0

| NFPA-S =

| AutoignitionPt =

'''2,6-Lutidine''' is a natural [[heterocyclic compound|heterocyclic]] [[aromaticity|aromatic]] [[organic compound]] with the formula (CH₃)₂C₅H₃N. It is one of several [[methyl group|dimethyl]]-substituted derivative of [[pyridine]], all of which are referred to as [[Lutidine|lutidines]]. It is a colorless liquid with mildly basic properties and a pungent, noxious odor.

==Occurrence and production==

It was first isolated from the [[base (chemistry)|basic]] fraction of [[coal tar]] and from [[Dippel's oil|bone oil]].<ref name="M"/>

A laboratory route involves condensation of [[ethyl acetoacetate]], formaldehyde, and an ammonia source to give a bis(carboxy ester) of a 2,6-dimethyl-1,4-dihydropyridine, which, after hydrolysis, undergoes decarboxylation.<ref>{{cite journal|title=2,6-Dimethylpyridine|first1=Alvin |last1=Singer|first2= S. M.|last2=McElvain|journal=Organic Syntheses|year=1934|volume= 14|page=30|doi=10.15227/orgsyn.014.0030}}</ref>

It is produced industrially by the reaction of [[formaldehyde]], [[acetone]], and [[ammonia]].<ref name=Ullmann>{{Ullmann|first1=Shinkichi|last1=Shimizu|first2=Nanao|last2=Watanabe|first3=Toshiaki|last3=Kataoka|first4=Takayuki|last4= Shoji|first5=Nobuyuki|last5=Abe|first6=Sinji|last6=Morishita|first7=Hisao|last7=Ichimura|title=Pyridine and Pyridine Derivatives|year=2007|doi=10.1002/14356007.a22_399}}</ref>

==Uses==

2,6-Lutidine has been evaluated for use as a food additive owing to its nutty aroma when present in solution at very low concentrations.

Due to the steric effects of the two methyl groups, 2,6-lutidine is less nucleophilic than pyridine. Protonation of lutidine gives '''lutidinium''', [(CH₃)₂C₅H₃NH]⁺, salts of which are sometimes used as a weak acid because the conjugate base (2,6-lutidine) is so weakly coordinating. In a similar implementation, 2,6-lutidine is thus sometimes used in [[organic synthesis]] as a [[Steric effects|sterically hindered]] mild base.<ref>{{cite journal|title=Synthesis of 2′-Deoxyribonucleosides: Β-3′,5′-Di-''o''-benzoylthymidine

|first1=Daniel R. |last1=Prudhomme|first2=Minnie |last2=Park|first3=Zhiwei |last3=Wang|first4=Jason R. |last4=Buck|first5=Carmelo J.|last5=Rizzo

|journal=Org. Synth.|year=2000|volume=77|page=162|doi=10.15227/orgsyn.077.0162}}</ref>

One of the most common uses for 2,6-lutidine is as a [[non-nucleophilic base]] in [[organic synthesis]]. It takes part in the formation of [[silyl ether]]s as shown in multiple studies.<ref>{{cite journal|last1=Corey |first1=E. J. |last2=Cho |first2=H. |last3=Rücker |first3=C. |last4=Hua |first4=D. H. |date=1981 |title=Studies with trialkylsilyltriflates: new syntheses and applications |journal=Tetrahedron Letters |volume=22 |issue=36 |pages=3455–3458 |doi=10.1016/s0040-4039(01)81930-4}}</ref><ref>{{cite journal|first1=Xavier |last1=Franck |first2=Bruno |last2=Figadère |first3=André |last3=Cavé |title=Mild deprotection of ''tert''-butyl and ''tert''-amyl ethers leading either to alcohols or to trialkylsilyl ethers |journal=Tetrahedron Letters |volume=36 |issue=5 |date=1995 |pages=711–714 |issn=0040-4039 |doi=10.1016/0040-4039(94)02340-H}}</ref>

Oxidation of 2,6-lutidine with air gives [[2,6-Diformylpyridine|2,6-diformylpyridine]]:

:C₅H₃N(CH₃)₂ + 2 O₂ → C₅H₃N(CHO)₂ + 2 H₂O

== Biodegradation ==

The biodegradation of pyridines proceeds via multiple pathways.<ref>{{cite journal|title=Biochemical Interpretation of Quantitative Structure-Activity Relationships (QSAR) for Biodegradation of ''N''-Heterocycles: A Complementary Approach to Predict Biodegradability|last1=Philipp|first1=Bodo|last2=Hoff|first2=Malte|last3=Germa|first3=Florence|last4=Schink|first4=Bernhard|last5=Beimborn|first5=Dieter|last6=Mersch-Sundermann|first6=Volker|journal=Environmental Science & Technology|year=2007|volume=41|issue=4 |pages=1390–1398|doi=10.1021/es061505d|pmid=17593747|bibcode=2007EnST...41.1390P |url=https://kops.uni-konstanz.de/bitstreams/6a1d118f-e52a-478f-8f9e-d8cbd9384229/download}}</ref> Although [[pyridine]] is an excellent source of carbon, nitrogen, and energy for certain microorganisms, methylation significantly retards degradation of the pyridine ring. In soil, 2,6-lutidine is significantly more resistant to microbiological degradation than any of the [[picoline]] isomers or [[2,4-Lutidine|2,4-lutidine]].<ref>{{cite journal|last1=Sims|first1=G. K.|first2=L. E.|last2=Sommers|year=1985|title=Degradation of pyridine derivatives in soil|journal=Journal of Environmental Quality|volume=14|issue=4|pages=580–584|doi=10.2134/jeq1985.00472425001400040022x|bibcode=1985JEnvQ..14..580S }}</ref> Estimated time for complete degradation was over 30 days.<ref>{{cite journal|last1=Sims|first1=G. K.|first2=L. E.|last2=Sommers|year=1986|title=Biodegradation of Pyridine Derivatives in Soil Suspensions|journal=Environmental Toxicology and Chemistry |volume=5|issue=6|pages=503–509|doi=10.1002/etc.5620050601}}</ref>

== See also ==

* [[3,5-Lutidine]]

* [[2,4-Lutidine]]

* [[2,6-Dimethylpiperidine]]

* [[2,4,6-Trimethylpyridine]] (collidine)

==Toxicity==

Like most alkylpyridines, the [[LD50|LD₅₀]] of 2,6-dimethylpyridine is modest, being 400 mg/kg (oral, rat).<ref name=Ullmann/>

== References ==

{{Reflist}}

{{DEFAULTSORT:Lutidine, 2,6-}}

[[Category:Pyridines]]

[[Category:Non-nucleophilic bases]]