N-(N-BUTYL)THIOPHOSPHORIC TRIAMIDE

N-(N-Butyl)thiophosphoric Triamide is the organophosphorus compound with the formula SP(NH2)2(NHC4H9). 
N-(N-Butyl)thiophosphoric Triamide is an amide of thiophosphoric acid. 
A white solid, N-(N-Butyl)thiophosphoric Triamide is an "enhanced efficiency fertilizer", intended to limit the release of nitrogen-containing gases following fertilization.

CAS:    94317-64-3
MF:    C4H14N3PS
MW:    167.21
EINECS:    435-740-7

Synonyms
N-(N-BUTYL)THIOPHOSPHORIC TRIAMIDE;N-BUTYLTHIOPHOSPHORIC TRIAMIDE;butyl-phosphorothioictriamid;N-(N-BUTYL)-THIOPHORIC TRIAMIDE (NBPT);N-(n-Butyl)thiophosphoricTriamide=NBPT;N-(N-BUTYL)THIOPHOSPHORICACID;Butylphosphorothioic triamide;N-(n-Butyl)thiophosphoric triamide ,97%

Regarding its chemical structure, the molecule features tetrahedral phosphorus bonded to sulfur and three amido groups.
N-(N-Butyl)thiophosphoric Triamide inhibits the enzyme urease, a widespread component of soil microorganisms. Urease converts urea, a commonly used nitrogen fertilizer, to ammonia, which can volatilize before it is absorbed by crops. 
N-(N-Butyl)thiophosphoric Triamide is called an enhanced efficiency nitrogen fertilizer (EENF) because it fosters improved intake of nitrogen, potentially allowing the grower to decrease the amount of urea applied to a crop.
N-(N-Butyl)thiophosphoric Triamide is a urease inhibitor used primarily in agricultural applications. 
N-(N-Butyl)thiophosphoric Triamide is a triamide herbicide that inhibits the plant enzyme fatty acid synthase. 
N-(N-Butyl)thiophosphoric Triamide has been shown to inhibit the uptake of glycol ethers, such as glycol esters, into plants by acting on the glycol ester hydroxyl group. 
N-(N-Butyl)thiophosphoric Triamide also inhibits the synthesis of fatty acids in plants and reduces lipid content in perennial ryegrass and solanum tuberosum. 
N-(N-Butyl)thiophosphoric Triamide also inhibits nitrous oxide emissions from wastewater treatment plants.
N-(N-Butyl)thiophosphoric Triamide, also known as agrotain or NBPT, is an organophophorus compound which appears as a white solid. 
The general application of this material is to limit the release of nitrogen-containing gases following fertilization. 
N-(N-Butyl)thiophosphoric Triamide has some unique chemistry, including a tetrahedral phosphorus bonded to sulfur and three amide groups.

N-(N-Butyl)thiophosphoric Triamide Chemical Properties
Melting point: 58-60°C
Boiling point: 277.4±23.0 °C(Predicted)
Density: 1.171±0.06 g/cm3(Predicted)
Vapor pressure: 0.001-1.7Pa at 25℃
Fp: 96°C
Storage temp.: Keep in dark place,Inert atmosphere,2-8°C
Solubility: DMSO (Sparingly), Methanol (Slightly)
Form: Solid
pka: 6.23±0.70(Predicted)
Color: White to Off-White
Water Solubility: 4.3 g/L at 25 ºC
Sensitive: Stench
InChIKey: HEPPIYNOUFWEPP-UHFFFAOYSA-N
LogP: -0.32-0.444 at 20-25℃
CAS DataBase Reference: 94317-64-3(CAS DataBase Reference)
EPA Substance Registry System: PN-(N-Butyl)thiophosphoric Triamide (94317-64-3)

Use
N-(N-Butyl)thiophosphoric Triamide functions as an inhibitor of the enzyme urease.
Urease, pervasive in soil microorganisms, converts urea into ammonia, which is susceptible to volatilization if produced faster than it can be utilized by plants. 
Approximately 0.5% by weight NBPT is mixed with the urea.
N-(N-Butyl)thiophosphoric Triamide is currently one of the most effective soil urease inhibitors. 
As a soil nitrogen fertilizer inhibitor, N-(N-Butyl)thiophosphoric Triamide is highly efficient, non-toxic, has no side effects on soil, and naturally degrades into ammonia and phosphorus in the soil. 
N-(N-Butyl)thiophosphoric Triamide can also be absorbed as fertilizer by crop roots and reduces the toxicity of ammonia to seed germination and seedling growth. 
The effect is an excellent soil nitrogen fertilizer enzyme inhibitor.

Synthesis
General procedure for the synthesis of n-butylthiophosphoric triamine from the compound (CAS: 6141-81-7): first, ammonia was passed through cold hydrazine and externally observed until liquid ammonia was formed. 
A cooling device was started in a four-necked flask equipped with a stirrer to maintain the reaction temperature at -45°C. 
Subsequently, 12.75 g of liquid ammonia was added to the flask and the pre-cooled reaction solution was added dropwise stepwise. 
The dropwise addition process was controlled to be completed within 1.5 hours. 
Samples were taken during the reaction and when the content of N-butylamino thiophosphoryl dichloride decreased to 2% of the total mass, the reaction temperature was raised to 25°C. 
The reaction was continued until the substitution reaction was completed, with a total reaction time of 2 h 5 min. 
At the end of the reaction, the product was filtered, washed and vaporized, and finally recrystallized from n-hexane to obtain N-n-butylaminophosphorothioic acid triamine with a purity of 98.7% and a yield of 95.1%.