Metribuzin

{{Chembox

| ImageFile = Metribuzin.svg

| ImageSize =

| ImageAlt = Skeletal formula of metribuzin

| ImageFile1 = Metribuzin-3D-spacefill.png

| ImageAlt1 = Space-filling model of the metribuzin molecule

| PIN = 3-Amino-5-tert-butyl-2-(methylsulfanyl)-1,2,4-triazin-5(4H)-one

| OtherNames = 4-Amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one

| Section1 = {{Chembox Identifiers

| CASNo =21087-64-9

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = QO836138OV

| PubChem =30479

| SMILES = CC(C)(C)C1=NN=C(N(C1=O)N)SC

| ChemSpiderID = 28287

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

| ChEBI = 34846

| InChI = 1/C8H14N4OS/c1-8(2,3)5-6(13)12(9)7(14-4)11-10-5/h9H2,1-4H3

| InChIKey = FOXFZRUHNHCZPX-UHFFFAOYAI

| StdInChI = 1S/C8H14N4OS/c1-8(2,3)5-6(13)12(9)7(14-4)11-10-5/h9H2,1-4H3

| StdInChIKey = FOXFZRUHNHCZPX-UHFFFAOYSA-N}}

| Section2 = {{Chembox Properties

| C=8 | H=14 | N=4 | O=1 | S=1

| Appearance = Colorless, crystalline solid

| Density = 1.31 g/cm³

| MeltingPtC = 125

| BoilingPt =

| Solubility = 0.1% (20 °C)

| VaporPressure = 0.0000004 mmHg (20 °C){{PGCH|0430}}

}}

| Section3 = {{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt =

| PEL = none

| IDLH = N.D.

| REL = 5 mg/m³

}}

| Section4 =

}}

Metribuzin (4-amino-6-tert-butyl-3-(methylthio)-1,2,4-triazin-5(4H)-one) is a herbicide used both pre- and post-emergence in crops including soy bean, potatoes, tomatoes and sugar cane.

It acts by inhibiting photosynthesis by disrupting photosystem II.{{cite book |author1=Terence Robert Roberts |author2=David Herd Hutson |title=Metabolic Pathways of Agrochemicals: Herbicides and plant growth regulators |url=https://books.google.com/books?id=uC2-Ocob_MMC&pg=PA662 |access-date=25 May 2012 |date=17 July 1998 |publisher=Royal Society of Chemistry |isbn=978-0-85404-494-8 |pages=662–}} It is widely used in agriculture and has been found to contaminate groundwater.{{Cite journal |last1 = Undabeytia |first1 = T. S. |last2 = Recio |first2 = E. |last3 = Maqueda |first3 = C. |last4 = Morillo |first4 = E. |last5 = Gómez-Pantoja |first5 = E. |last6 = Sánchez-Verdejo |first6 = T. |doi = 10.1002/ps.2060 |title = Reduced metribuzin pollution with phosphatidylcholine-clay formulations |journal = Pest Management Science |volume = 67 |issue = 3 |pages = 271–278 |year = 2011 |pmid = 21308953|doi-access = free }}

Metribuzin is produced by reacting one mole of 4-amino-6-tert-butyl-3-mercapto-(1,2,4)triazin-5(4H)one and half a mole of dimethyl sulfonate which react at 57°C in presence of sulfuric acid media about 7 hours and transfer methyl (CH₃) from triazine to metribuzin and product formed 1 mole of metribuzin and half mole of sulfuric acid and later neutralized with soda ash and then purified.{{citation needed|date=August 2022}}

MP=125°C, BP=132°C, and cause dust explosion if enough amount of energy absorbed by it.{{citation needed|date=August 2022}}