Tert-Butyl Mercaptan

Tert-Butyl Mercaptan

Tert-Butyl Mercaptan

Tert-Butyl Mercaptan= TBM = tert-Butylthiol= 2-methylpropane-2-thiol = t-Butyl Mercaptan = t-Butylthiol = 2-Propanethiol, 2-methyl- = t-Butylmercaptan
Other names: tert-Butanethiol; tert-Butylmercaptan; tert-Butylthiol; 1,1-Dimethylethanethiol; 2-Isobutanethiol; 2-Methyl-2-propanethiol; tert-C4H9SH; t-Butyl mercaptan; tert-Butyl hydrosulfide; 2-Methyl-2-propylthiol; tertiary-Butyl mercaptan; 2-methylpropane-2-thiol

Tertiary butyl mercaptan (TBM) belongs to the alkyl mercaptan family and possesses a characteristic odor.

EC / List no.: 200-890-2
CAS no.: 75-66-1
Mol. formula: C4H10S

2-methylpropane-2-thiol
2-Propanethiol, 2-methyl-
CAS names: 2-Propanethiol, 2-methyl-

IUPAC names: 
2-methylpropane-2-thiol
2-Propanethiol, 2-methyl
tert-Butyl Mercaptan
Tertiobutylmercaptan

BUTANETHIOL
1-BUTANETHIOL
BUTYL MERCAPTAN
1-BUTYL MERCAPTAN
BUTYLTHIOL
1-MERCAPTOBUTANE
N-BUTANETHIOL
N-BUTYL MERCAPTAN
N-BUTYL THIOALCOHOL
N-BUTYLTHIOL
THIOBUTYL ALCOHOL

The tertio-butyl mercaptan (TBM) is a key raw material for agrochemical synthesis.
TBM is also a raw material used in gas odorant blends.

Tertiary butyl mercaptan (TBM) is a malodorant that is added to natural gas in small quantities to aid in its detection

Tert-Butyl Mercaptan (TBM), also known as 2-methylpropane-2-thiol, 2-methyl-2-propanethiol, tert-butyl mercaptan (TBM), and t-BuSH, is an organosulfur compound with the formula (CH3)3CSH
Tert-Butyl Mercaptan is a component in several Gas Odorants for use in odorizing natural gas so that leaks can be detected by smell before explosive levels are reached. 
Tert-Butyl Mercaptan is also used as a chemical intermediate for synthesis of agrichemicals and other chemical substances.

tert-Butylthiol, also known as 2-methylpropane-2-thiol, 2-methyl-2-propanethiol, tert-butyl mercaptan (TBM), and t-BuSH, is an organosulfur compound with the formula (CH3)3CSH. 
This thiol is used as an odorant for natural gas, which is otherwise odorless.

Tert-Butyl mercaptan (2-methyl-2-propanethiol, CAS # 75-66-1) is a highly odorous material, with an odor threshold of < 1ppb. 

Tert-Butyl mercaptan is a component in several Scentinel Gas Odorants for use in odorizing natural gas so that leaks can be detected by smell before explosive levels are reached. It is also used as a chemical intermediate for synthesis of agrichemicals and other chemical substances.

Use: The tertio-butyl mercaptan (TBM) is a key raw material for agrochemical synthesis. TBM is also a raw material used in gas odorant blends.

Synonyms:
tert-    butane thiol
tert-    butanethiol
tert-    butyl thiol
tert-    butylmercaptan
tert-    butylthiol
1,1-    dimethylethanethiol
2-    methyl propane-2-thiol
2-    methyl-2-propane thiol
2-    methyl-2-propanethiol
2-    methyl-2-propanthiol
2-    methylpropane-2-thiol
     propane-2-thiol, 2-methyl-
2-    propanethiol, 2-methyl-

Applications
Agrochemicals
Chemical Intermediate
Gas Odorant
Other Chemicals

Preferred IUPAC name: 2-Methylpropane-2-thiol

Other names
t-BuSH
2-Methylpropane-2-thiol
2-Methyl-2-propanethiol
tert-Butyl mercaptan

2-Methyl-2-propanethiol
tert-Butyl mercaptan
75-66-1
2-Methylpropane-2-thiol
tert-Butylthiol
tert-Butanethiol
2-Propanethiol, 2-methyl-
T-BUTYL MERCAPTAN
tert-Butylmercaptan
t-Butylmercaptan
2-Isobutanethiol
tertiary-Butyl mercaptan
1,1-Dimethylethanethiol
tert-butyl thiol
UNII-489PW92WIV
2-methyl-propane-2-thiol
489PW92WIV
2-Methyl-2-propanethiol, 99%
TBM
t-BuSH
99224-24-5
HSDB 1611
EINECS 200-890-2
BRN 0505947
tertbutanethiol
t-butanethiol
terbutyl mercaptan
tBuSH
tert.-butylmercaptan
tert-C4H9SH
tert. butyl mercaptan
tert.-butyl mercaptan
HS-t-Bu
tert-Butyl hydrosulfide
2-methyl-2propanethiol
2-methylpropan-2-thiol
2-Methyl-2-propylthiol

CAS Number: 75-66-1 

Properties
Chemical formula: C4H10S
Molar mass: 90.18 g·mol−1
Appearance: Colorless, clear liquid
Density:0.8 g/mL
Melting point: −0.50 °C (31.10 °F; 272.65 K)
Boiling point: 62 to 65 °C (144 to 149 °F; 335 to 338 K)

Preparation of Tert-Butyl Mercaptan
At least one publication has listed tert-butylthiol as a very minor component of cooked potatoes, but because the tert-butyl moiety is very rare in natural products, other sources doubt the existence of natural sources of the compound. 
It was first prepared in 1890 by Leonard Dobbin by the reaction of zinc sulfide and t-butyl chloride.

The compound was later prepared in 1932 by the reaction of the Grignard reagent, t-BuMgCl, with sulfur to give the corresponding thiolate, followed by hydrolysis.
This preparation is shown below:

t-BuMgCl + S → t-BuSMgCl
t-BuSMgCl + H2O → t-BuSH + Mg(OH)Cl
It is currently prepared industrially by the reaction of isobutylene with hydrogen sulfide over a clay (silica alumina) catalyst

2-Methyl-2-propanethiol Chemical Properties,Uses and Production

Description
tert-Butylthiol, also known as 2-methyl propane-2-thiol, 2- methyl-2-propane thiol, tert-butyl mercaptan (TBM), and t-BuSH, is an organo sulfur compound with the formula (CH3)3CSH. This thiol may have been used as a flavoring agent, as an odorant for natural gas (which is odorless), and also in a wide range of organic reactions.

Chemical Properties
liquid with an exceedingly unpleasant smell

Uses
2-Methyl-2-propanethiol was used in reaction of 2-methyl-2-propanethiol on Mo(110) using temperature programmed reaction, high resolution electron enegy loss and X-ray photoelectron spectroscopies. It was used in the synthesis of chain-transfer agents for reversible addition-fragmentation chain-transfer copolymerization of vinylidene chloride and methyl acrylate.

Uses
Tert-Butylthiol is the main ingredient in many gas odorant blends. It is always utilized as a blend of other compounds, typically dimethyl sulfide, methyl ethyl sulfide, tetrahydrothiophene or other mercaptans (isopropyl mercaptan, sec-butyl mercaptan and/or n-butyl mercaptan, due to its rather high melting point of 273 K. These blends are used only with natural gas and not propane, as the boiling points of these blends and propane are quite different. As propane is delivered as a liquid and vaporizes to gas when being delivered to the appliance, the vapor liquid equilibrium would substantially reduce the amount of odorant blend in the vapor.
Tert – Butyl thiol has been listed on the European Food Safety Authority (FL-no: 12.174) as a flavor additive. There is no indication of what flavor or flavors it may have been used in. It has been removed from this list.

Preparation
tert-Butyl thiol likely does not occur naturally, but at least one publication has listed it as a very minor component of cooked potatoes. The compound was first prepared in 1890 by Leonard Dobbin by the reaction of zinc sulfide and t-butyl chloride.
The compound was later prepared in 1932 by the reaction of the Grignard reagent, t-BuMgCl, with sulfur to give the corresponding thiolate, followed by hydrolysis. This preparation is shown below:
t-BuMgCl + S → t-BuSMgCl
t-BuSMgCl + H2O → t-BuSH + Mg(OH)Cl
It is currently prepared industrially by the reaction of isobutylene with hydrogen sulfide over a clay (silica alumina) catalyst.

Reactions
tert-Butylthiol can react with metal alkoxides and acyl chlorides to form thiol esters, as shown in the equation :
In the reaction above, thallium (I) ethoxide converts to thallium (I) t-butyl thiolate. In the presence of diethyl ether, thallium (I) tbutylthiolate reacts with acyl chlorides to give the corresponding tertbutyl thioesters. Like other thio esters, it reverts back to tert-butylthiol by hydrolysis.
Lithium 2-methyl propane-2-thiolate can be prepared by treatment of tert-butyl thiol with lithium hydride in an aprotic solvent such as hexa methyl phosphorous triamide (HMPT). The resulting thiolate salt is a useful demethylating reagent. For example, treatment with 7- methyl guanosine gives guanosine. Other N-methylated nucleosides in tRNA are not demethylated by this reagent .

Hazard
Flammable, dangerous fire risk. Very toxic.

Safety Profile
Moderately toxic by intraperitoneal route. Mildly toxic by ingestion. An eye irritant. A very dangerous fire hazard when exposed to heat or flame. Can react vigorously with oxidizing materials. To fight fire, use alcohol foam, dry chemical, mist, fog. When heated to decomposition or on contact with acid or acid fumes it emits highly toxic fumes of SOx.

Safety
Even in well ventilated areas, extreme caution must be made when handling tert-butylthiol as it is a highly odorous chemical with an odor threshold of < 0.33 ppb. Extreme caution is not due to toxicity, but due to the significant odor and concerns that this odor would cause to the many individuals that might be exposed. The PEL for thiols of most types is 500 ppb, primarily due to reaction of nausea at levels of 2–3 ppm. The LC50 of tert-butylthiol is much, much higher.
Purification Methods
Dry the thiol for several days over CaO, then distil it from CaO. Purify it as for 2-methylpropane-1-thiol above. [Beilstein 1 H 383, 1 II 416, 1 III 1589, 1 IV 1634.]

Metal complexes
The anion derived from tert – butyl thiol forms complexes with various metals. One example is tetra kis (tert-butyl thiolato ) molybdenum (IV), Mo(t-BuS)4. This complex was prepared by treating MoCl4 with t-BuSLi :
Mo Cl4 + 4t-Bu S Li → Mo (t-BuS)4 + 4LiCl
Mo(t-BuS)4 is a dark red diamagnetic complex that is sensitive to air and moisture. The molybdenum center has a distorted tetra hedral coordination to four sulfur atoms, with overall D2 symmetry.
2-Methyl-2-propanethiol Preparation Products And Raw materials

Raw materials
Hydrogen Sulfide Tebutanol ISOBUTYLENE Hydrogen

Reactions
tert-Butylthiol can react with metal alkoxides and acyl chlorides to form thiol esters, as shown in the equation:

Reaction of tert-butylthiol with an acyl chloride.
Reaction of tert-butylthiol with an acyl chloride.
In the reaction above, thallium(I) ethoxide converts to thallium(I) t-butylthiolate. 
In the presence of diethyl ether, thallium(I) t-butylthiolate reacts with acyl chlorides to give the corresponding tert-butyl thioesters.
Like other thioesters, it reverts to tert-butylthiol by hydrolysis.

Lithium 2-methylpropane-2-thiolate can be prepared by treatment of tert-butylthiol with lithium hydride in an aprotic solvent such as hexamethylphosphoramide (HMPA). 
The resulting thiolate salt is a useful demethylating reagent. 
For example, treatment with 7-methylguanosine gives guanosine. 
Other N-methylated nucleosides in tRNA are not demethylated by this reagent.

Lithium 2-methylpropane-2-thiolate reaction with 7-methylguanosine.
Metal complexes
The anion derived from tert-butylthiol forms complexes with various metals.One example is tetrakis(tert-butylthiolato)molybdenum(IV), Mo(t-BuS)4. 
This complex was prepared by treating MoCl4 with t-BuSLi:[9]

MoCl4 + 4 t-BuSLi → Mo(t-BuS)4 + 4 LiCl
Mo(t-BuS)4 is a dark red diamagnetic complex that is sensitive to air and moisture. 
The molybdenum center has a distorted tetrahedral coordination to four sulfur atoms, with overall D2 symmetry.

Mo(t-BuS)4
Safety
Even in well ventilated areas, extreme caution must be made when handling tert-butylthiol as it is a highly odorous chemical with an odor threshold of <0.33 ppb.
Extreme caution is not due to toxicity, but due to the significant odor and the concern this odor could cause to individuals that might be exposed. 
The PEL for thiols of most types is 500 ppb[citation needed], primarily due to reaction of nausea at levels of 2–3 ppm.

Commercial use
tert-Butylthiol is the main ingredient in many gas odorant blends. 
tert-Butylthiol is always utilized as a blend of other compounds, typically dimethyl sulfide, methyl ethyl sulfide, tetrahydrothiophene or other mercaptans such as isopropyl mercaptan, sec-butyl mercaptan and/or n-butyl mercaptan, due to its rather high melting point of −0.5 °C (31.1 °F). 
These blends are used only with natural gas and not propane, as the boiling points of these blends and propane are quite different. 
Because propane is delivered as a liquid and vaporizes to gas when it is delivered to the appliance, the vapor liquid equilibrium would substantially reduce the amount of odorant blend in the vapor.

tert-Butylthiol has been listed on the European Food Safety Authority (FL-no: 12.174) as a flavor additive. 
There is no indication of what flavor(s) it may have been used in. 
tert-Butylthiol has been removed from this list.

See also
Butanethiol (butyl mercaptan)
Ethanethiol (ethyl mercaptan)

● Chemical Intermediate
● Odorant

PRODUCT: t-Butyl mercaptan

CAS #: 75-66-1

SYNONYM: 2-Methyl-2-Propanethiol; 2-Methyl-2-Propylthiol; 2-Propanethiol, 2-methyl-; tert-Butanethiol; tert-Butylthiol; 1,1-Dimethylethanethiol; 2-Isobutanethiol; tert-C4H9SH; t-Butyl mercaptan; tert-Butyl hydrosulfide; tertiary-Butyl mercaptan; 2-methylpropane-2-thiol;1,1-Dimethylethanethiol; 2-Isobutanethiol; 2-Methyl-2-propanethiol; 2-Propanethiol, 2-methyl-; 4-01-00-01634 (Beilstein Handbook Reference); BRN 0505947; EC 200-890-2; EINECS 200-890-2; HSDB 1611; t-Butylmercaptan; tert-Butanethiol; tert-Butyl mercaptan; tert-Butylmercaptan; tert-Butylthiol; tertiary-Butyl mercaptan; UNII-489PW92WIV; 2-Methylpropane-2-thiol; 2-Propanethiol, 2-methyl-; Superlist Names 2-Methyl-2-propanethiol; 2-Propanethiol, 2-methyl-;;t-Butyl mercaptan;t-Butanethiol; 2-Methyl-2-propanethiol

t-Butyl mercaptan uses and applications include: Odorant to permit detection of gas leaks; intermediate; bacterial nutrient

Tert-Butyl Mercaptan (TBM) is used as an odorant for natural gas, which is otherwise odorless. 
It may also have been used as a flavoring agent. 
TBM detector is can help you to know TBM concentration exactly with fast response and high precision and it can used in different environment.

t-butyl mercaptan (TBM): a sulfur odorant

Natural Gas Odorant: Tert-butyl mercaptan (TBM)
Tert-butyl mercaptan is one of the most commonly used odorants due to its high oxidation resistance, good soil penetration and recognized odor. 
Tert-butyl mercaptan generally cannot be used as a standalone odorant due to its high freezing point and so is most often found in blends.

The detection of natural gas leakage has long been a concern to the natural gas industry, but never more so than today. 
Increased public awareness of safety and huge increases in the cost of product liability litigation has resulted in a greater focus on gas odorization. 
While it must be recognized that no odorant will be 100% effective in warning of the presence of natural gas, basic knowledge about the properties and characteristics of odorants used for natural gas and an understanding about some of the potential problems in the odorization of such gas can be extremely helpful for those involved in the gas odorization process. 

Description: tert-Butylthiol, also known as 2-methyl propane-2-thiol, 2- methyl-2-propane thiol, tert-butyl mercaptan (TBM), and t-BuSH, is an organo sulfur compound with the formula (CH3)3CSH. This thiol may have been used as a flavoring agent, as an odorant for natural gas (which is odorless), and also in a wide range of organic reactions.
Chemical Properties: liquid with an exceedingly unpleasant smell
Uses: 2-Methyl-2-propanethiol was used in reaction of 2-methyl-2-propanethiol on Mo(110) using temperature programmed reaction, high resolution electron enegy loss and X-ray photoelectron spectroscopies. It was used in the synthesis of chain-transfer agents for reversible addition-fragmentation chain-transfer copolymerization of vinylidene chloride and methyl acrylate.
Uses: Tert-Butylthiol is the main ingredient in many gas odorant blends. 
It is always utilized as a blend of other compounds, typically dimethyl sulfide, methyl ethyl sulfide, tetrahydrothiophene or other mercaptans (isopropyl mercaptan, sec-butyl mercaptan and/or n-butyl mercaptan, due to its rather high melting point of 273 K. 
These blends are used only with natural gas and not propane, as the boiling points of these blends and propane are quite different. 
As propane is delivered as a liquid and vaporizes to gas when being delivered to the appliance, the vapor liquid equilibrium would substantially reduce the amount of odorant blend in the vapor.
Tert – Butyl thiol has been listed on the European Food Safety Authority (FL-no: 12.174) as a flavor additive. 
There is no indication of what flavor or flavors it may have been used in. It has been removed from this list.
Preparation: tert-Butyl thiol likely does not occur naturally, but at least one publication has listed it as a very minor component of cooked potatoes. 
The compound was first prepared in 1890 by Leonard Dobbin by the reaction of zinc sulfide and t-butyl chloride.
The compound was later prepared in 1932 by the reaction of the Grignard reagent, t-BuMgCl, with sulfur to give the corresponding thiolate, followed by hydrolysis. 
This preparation is shown below:
t-BuMgCl + S → t-BuSMgCl
t-BuSMgCl + H2O → t-BuSH + Mg(OH)Cl
It is currently prepared industrially by the reaction of isobutylene with hydrogen sulfide over a clay (silica alumina) catalyst.

Reactions: tert-Butylthiol can react with metal alkoxides and acyl chlorides to form thiol esters, as shown in the equation :
In the reaction above, thallium (I) ethoxide converts to thallium (I) t-butyl thiolate. 
In the presence of diethyl ether, thallium (I) tbutylthiolate reacts with acyl chlorides to give the corresponding tertbutyl thioesters. 
Like other thio esters, it reverts back to tert-butylthiol by hydrolysis.
Lithium 2-methyl propane-2-thiolate can be prepared by treatment of tert-butyl thiol with lithium hydride in an aprotic solvent such as hexa methyl phosphorous triamide (HMPT). The resulting thiolate salt is a useful demethylating reagent. For example, treatment with 7- methyl guanosine gives guanosine. Other N-methylated nucleosides in tRNA are not demethylated by this reagent .
Hazard: Flammable, dangerous fire risk. Very toxic.

Safety Profile:Moderately toxic by intraperitoneal route. Mildly toxic by ingestion. An eye irritant. A very dangerous fire hazard when exposed to heat or flame. Can react vigorously with oxidizing materials. To fight fire, use alcohol foam, dry chemical, mist, fog. When heated to decomposition or on contact with acid or acid fumes it emits highly toxic fumes of SOx.
Safety    Even in well ventilated areas, extreme caution must be made when handling tert-butylthiol as it is a highly odorous chemical with an odor threshold of < 0.33 ppb. Extreme caution is not due to toxicity, but due to the significant odor and concerns that this odor would cause to the many individuals that might be exposed. The PEL for thiols of most types is 500 ppb, primarily due to reaction of nausea at levels of 2–3 ppm. The LC50 of tert-butylthiol is much, much higher.
Purification Methods: Dry the thiol for several days over CaO, then distil it from CaO. 
Purify it as for 2-methylpropane-1-thiol above. [Beilstein 1 H 383, 1 II 416, 1 III 1589, 1 IV 1634.]
Metal complexes    The anion derived from tert – butyl thiol forms complexes with various metals. 
One example is tetra kis (tert-butyl thiolato ) molybdenum (IV), Mo(t-BuS)4. This complex was prepared by treating MoCl4 with t-BuSLi :
Mo Cl4 + 4t-Bu S Li → Mo (t-BuS)4 + 4LiCl
Mo(t-BuS)4 is a dark red diamagnetic complex that is sensitive to air and moisture. The molybdenum center has a distorted tetra hedral coordination to four sulfur atoms, with overall D2 symmetry.

ODORANT COMPONENTS 
Since natural gas odorants are virtually all blends of two or more components, we must first gain some knowledge of the components used. 
These components are divided into three general groups: 

Mercaptans 
Alkyl Sulfides 
Cyclic Sulfides 

Mercaptans 

• Tertiary Butyl Mercaptan (TBM) 
Leading component used in natural gas odorants 
Most resistance to oxidation of the mercaptans 
Best in soil penetrability of the mercaptans 
Low odor threshold “Gassy” odor 
High freeze point (34°F) 
Usual concentration – 75-80% of the total blend

SOIL PENETRATION:
This has been known and discussed more widely than any other potential problem concerning the odorization of natural gas. 
It is associated with the passage of escaped natural gas through soil. 
Depending upon the facts and circumstances surrounding the escape of natural gas (i.e. rate of leak, amount of soil through which the gas must pass, etc.), certain types of soil — clay being the worst — can remove some or all of any odorant from the natural gas for a period of time. 
Tertiary Butyl Mercaptan (TBM) is considered the best of the mercaptans in soil penetration.

MASKING/SCRUBBING/CONTAMINATION:
These potential problems are associated with “wet” natural gas or gas containing high amounts of C4+Hydrocarbons. 
These Hydrocarbons can “mask” or cover up the odorant in the gas stream. 
They also tend to gather in low areas of the pipeline and “scrub out” or remove the odorant as the gas flows through the liquid.
Another problem is hydrocarbon contamination of the odorant in by-pass vaporization type odorizers. 
The obvious solution is to remove the liquids at the processing plant, however this is not always possible. 
Therefore either higher rates of an all mercaptan blend containing Tertiary Butyl Mercaptan as the major component or addition of difficult to mask odorants such as Secondary Butyl Mercaptan or etrahydrothiophene should be attempted

2-Methyl-2-propanethiol
tert-Butyl mercaptan
75-66-1
2-Methylpropane-2-thiol
tert-Butylthiol
tert-Butanethiol
2-Propanethiol, 2-methyl-
T-BUTYL MERCAPTAN
tert-Butylmercaptan
t-Butylmercaptan
2-Isobutanethiol
tertiary-Butyl mercaptan
1,1-Dimethylethanethiol
tert-butyl thiol
UNII-489PW92WIV
2-methyl-propane-2-thiol
489PW92WIV
2-Methyl-2-propanethiol, 99%
TBM
t-BuSH
99224-24-5
HSDB 1611
EINECS 200-890-2
BRN 0505947
tertbutanethiol
t-butanethiol
terbutyl mercaptan
tBuSH
tert.-butylmercaptan
tert-C4H9SH
tert. butyl mercaptan
tert.-butyl mercaptan
HS-t-Bu
tert-Butyl hydrosulfide
2-methyl-2propanethiol
2-methylpropan-2-thiol
2-Methyl-2-propylthiol
3374-16-1
DSSTox_CID_6418
EC 200-890-2
DSSTox_RID_78108
DSSTox_GSID_26418
4-01-00-01634 (Beilstein Handbook Reference)
CHEMBL3182458
DTXSID0026418
AMY28695
ZINC4706566
Tox21_200874
2-$l^{1}-sulfanyl-2-methylpropane
MFCD00004857
NSC229569
STL264247
2-METHYL-2-PROPANE-D9-THIOL
AKOS000121277
MCULE-6147507012
NSC-229569
CAS-75-66-1
NCGC00248858-01
NCGC00258428-01
DB-000158
FT-0612928
M0405
X7332
Q973473
W-109267
F0001-1902
16528-55-5

Applications
Odorants are added artificially to natural gas to allow for human leak detection. Local distribution companies (LDCs) employ numerous “sniffers” who judge odorant level in the natural gas product, while generating data from field reports, customer input, and modeling programs.

However, interstate pipelines span hundreds of miles that cross through various territories. 
Dispatching “sniffers” across vast distances is both time-consuming and costly. 
While “sniff testing” complies and satisfies the minimum criteria set forth in CFR, Title 49, Part 192.625, an on-line process analyzer would provide the same testing functionality with much richer quantitative data (one example: continuous trend data as opposed to discrete data points).

On-line odorant analysis allows the transmission companies to schedule the minimum required visits to perform sniffing, and optimize their odorant distribution system in real-time. 
Secondary benefits allow them to optimize their pipeline performance by studying lag times, odorizer performance, fading effects, and other odorant issues.

The OMA measures various odorants including:

methanethiol | methyl mercaptan 
ethanethiol | ethyl mercaptan
tetrahydrothiophene | THT
tert-butylthiol | tert-butyl mercaptan 

OTHER MERCAPTANS OF ATAMAN CHEMICALS THAT MIGHT BE OF INTEREST :
Our Mercaptans are used in diverse applications, ranging from agricultural supplements to polymerization modifiers.

n-Butyl Mercaptan 109-79-5 203-705-3 CH3(CH2)2CH2SH 
sec-Butyl Mercaptan 513-53-1 208-165-2 CH3CH2CH(SH)CH3 
tert-Butyl Mercaptan 75-66-1 200-890-2 (CH3)3CSH 
Cyclohexyl Mercaptan 1569-69-3 216-378-7 C6H11SH 
n-Decyl Mercaptan 143-10-2 205-584-2 CH3(CH2)8CH2SH 
Dipentene Dimercaptan 4802-20-4 225-363-4 C10H18(SH)2 2
n-Dodecyl Mercaptan 112-55-0 203-914-1 CH3(CH2)10CH2SH 
tert-Dodecyl Mercaptan 25103-58-6 246-619-1 (tert-C12H25)SH 
Ethyl Mercaptan 75-08-1 200-837-3 CH3CH2SH 
n-Hexyl Mercaptan 111-31-9 203-857-0 CH3(CH2)4CH2SH 
Isobutyl Mercaptan 513-44-0 208-162-6 (CH3)2CHCH2SH 
Isopropyl Mercaptan 75-33-2 200-861-4 (CH3)2CHSH 
tert-Nonyl Mercaptan 25360-10-5 246-896-9 (tert-C9H19)SH 
n-Octyl Mercaptan 111-88-6 203-918-1 CH3(CH2)6CH2SH 
n-Propyl Mercaptan

SPECIALTY ORGANOSULFUR COMPOUNDS OF ATAMAN CHEMICALS: 
Di-(2-Hydroxethyl) Disulfide 1892-29-1 217-576-6 HOCH2CH2SSCH2CH2OH 
Dimethyl-3,3’-Thiodipropionate 4131-74-2 223-948-9 CH3OC(O)CH2CH2SCH2CH2C(O)OCH3 
2-Ethylhexyl-3-Mercaptopropionate 50448-95-8 256-589-1 HSCH2CH2C(O)OCH2CH(C2H5)(CH2)3CH3 
2-(Ethylthio)ethanol 110-77-0 203-802-0 CH3CH2SCH2CH2OH 
2-Hydroxethyl-n-Octyl Sulfide
2-Mercaptoethanol 60-24-2 200-464-6 HSCH2CH2OH 
3-Mercapto-1-Propanol 19721-22-3 – HSCH2CH2CH2OH 
Methyl-3-Mercaptopropionate 2935-90-2 220-912-4 HSCH2CH2C(O)OCH3 
Sodium Methyl Mercaptide 5188-07-8 225-969-9 Na SCH3 
Sulfolane(Tetrahydrothiophene-1,1- 126-33-0 204-783-1 C4H8O2S 
Sulfolene (2,5-Dihydrothiophene-1,1-Dioxide) 77-79-2 201-059-7 C4H6O2S 

SULFIDES, DISULFIDES & POLYSULFIDES OF ATAMAN CHEMICALS :
SULFIDATION & ANTI COKING (SPIKING) APPLICATIONS

Diethyl Sulfide 352-93-2 206-526-9 C4H10S 
Dimethyl Disulfide 624-92-0 210-871-0 CH3SSCH3 
Dimethyl Sulfide 75-18-3 200-846-2 C2H6S 62.14 854 37 
Di-tert-Butyl Polysulfide (TBPS 454) 68937-96-2 273-103-3 (CH3)3CS4C(CH3)3
Di-tert-Dodecyl Polysulfide (TDPS 320) 68425-15-0 270-335-7 (tert-C12H25)S3(tert-C12H25)
Di-tert-Dodecyl Polysulfide (TDPS 532) 68425-15-0 270-335-7 (tert-C12H25)S5(tert-C12H25)
Di-tert-Nonyl Polysulfide (TNPS 537) 68425-16-1 270-336-2 (tert-C9H19)S5(tert-C9H19)

Acute oral toxicity
t-Butyl Mercaptan : LD50: 4,729 mg/kg

Species: Rat
Sex: male
Acute inhalation toxicity
t-Butyl Mercaptan : LC50: 98.3 mg/l
Exposure time: 4 h
Species: Rat
Sex: male and female
Test atmosphere: vapor
Method: OECD Test Guideline 403
LC50: 81.9 mg/l
Exposure time: 4 h

Species: Rat
Sex: male
Test atmosphere: vapor
Method: OECD Test Guideline 403
LC50: 60.9 mg/l
Exposure time: 4 h
Species: Mouse
Sex: male
Test atmosphere: vapor
Method: OECD Test Guideline 403

Skin irritation
t-Butyl Mercaptan : No skin irritation
Eye irritation
t-Butyl Mercaptan : slight irritation. Information given is based on data obtained
from similar substances.

Sensitization
t-Butyl Mercaptan : May cause sensitization by skin contact.
Repeated dose toxicity
t-Butyl Mercaptan : Species: Rat, Male and female
Sex: Male and female

Description
General description
2-Methyl-2-propanethiol undergoes ring opening nucleophilic reaction with 3-isothiazolones and reaction kinetics studies suggested reaction was second order in thiol and third order overall[3].

Application
2-Methyl-2-propanethiol was used in reaction of 2-methyl-2-propanethiol on Mo(110) using temperature programmed reaction, high resolution electron enegy loss and X-ray photoelectron spectroscopies[1]. It was used in the synthesis of chain-transfer agents for reversible addition-fragmentation chain-transfer copolymerization of vinylidene chloride and methyl acrylate[2].

tert-Butyl mercaptan

Agent Name
tert-Butyl mercaptan

Alternative Name
2-Methyl-2-propanethiol

CAS Number
75-66-1

Formula
C4-H10-S

Major Category
Other Classes
tert-Butyl mercaptan formula graphical representation

Synonyms
2-Methyl-2-propanethiol; 1,1-Dimethylethanethiol; 2-Isobutanethiol; 2-Propanethiol, 2-methyl-; t-Butylmercaptan; tert-Butanethiol; t-Butyl mercaptan; tert-Butylmercaptan; tert-Butylthiol; tertiary-Butyl mercaptan; [ChemIDplus] UN2347

Category
Thiols

Description
Liquid with a strong skunky odor; [Merck Index] Clear colorless liquid with an unpleasant odor; [MSDSonline]

Sources/Uses
Used as an odorant for natural gas, a chemical intermediate, and a bacterial nutrient; [HSDB]

Comments
An eye and respiratory tract irritant; Inhalation of high concentrations can cause CNS depression; [ICSC] May cause mild skin and eye irritation, based on animal studies; Inhalation of high concentrations can cause CNS depression; [CHEMINFO] An irritant; May cause serious eye injury; [MSDSonline] See “THIOLS.”

1,1-Dimethylethanethiol
200-890-2 [EINECS]
2-Methyl-2-propanethiol [ACD/IUPAC Name]
2-Méthyl-2-propanethiol [French] [ACD/IUPAC Name]
2-Methyl-2-propanthiol [German] [ACD/IUPAC Name]
2-Methylpropane-2-thiol
2-Propanethiol, 2-methyl- [ACD/Index Name]
505947
75-66-1 [RN]
MFCD00004857
propane-2-thiol, 2-methyl-
TBM
t-Butyl mercaptan
t-Butylmercaptan
t-butylthiol
tert.-Butanethiol
TERT-BUTANETHIOL
tert-Butyl Mercaptan
tert-butyl thiol
tert-Butylmercaptan
Tert-Butylthiol [Wiki]
tertiary-Butyl mercaptan
TZ7660000
[75-66-1]
15800-78-9 [RN]
16528-55-5 [RN]
2-ISOBUTANETHIOL
2-METHYL-2-PROPANETHIOL|2-METHYLPROPANE-2-THIOL
2-Methyl-2-propylthiol
3374-16-1 [RN]
4-01-00-01634 (Beilstein Handbook Reference) [Beilstein]
99224-24-5 [RN]
EINECS 200-890-2
ETHYLTHIO, 1,1-DIMETHYL-
hydrogen tert-butylsulfanide
tert-Butyl hydrosulfide
tert-C4H9SH

Butyl mercaptan, tert-
2-methylpropane-2-thiol, tert-butanethiol, 2-methyl-2-propane thiol, tert-butylthiol, 1,1-dimethylethanethiol, 2-isobutanethiol, t-butyl mercaptan, tert-butyl hydrosulfide, 2-methyl-2-propyl thiol, 2-methylpropane-2-thiol, TBM, t-BuSH

USES/FORMS/SOURCES
USES
TERT-BUTYL MERCAPTAN is used as a chemical intermediate and odorant in natural gas. There is no simple relationship, however, between the intensity of its odor and its airborne concentration, however (Blanchard, 1976).
Little toxicological information is available for t-butyl mercaptan. In general, thiols are chemically reactive and can inactivate enzymes. In acute exposure studies in experimental animals, t-butyl mercaptan was less toxic than propyl mercaptan (RTECS).
The greatest hazard of t-butyl mercaptan may be its flammability. TERT-BUTYL MERCAPTAN can also act as a simple asphyxiant if levels reduce the concentrations of available oxygen.

FORMS
TERT-BUTYL MERCAPTAN, also called 2-METHYL-2-PROPANETHIOL, is a colorless, FLAMMABLE liquid with an extremely unpleasant, heavy skunk-like odor (HSDB). 
TERT-BUTYL MERCAPTAN is slightly soluble in water, and is soluble in alcohol, ether, and liquid hydrogen sulfide (HSDB)

SOURCES
“t-Butyl mercaptan is manufactured by the reaction of isobutylene and hydrogen sulfide in the presence of acid catalysts” (HSDB, 2003).

t-Butyl mercaptan’s production and subsequent use as an odorant in natural gas, as an intermediate, and as a bacterial nutrient may result in its release to the environment through various waste streams. 
If released to the atmosphere, t-butyl mercaptan will exist mainly in the vapor phase in the ambient atmosphere based on a vapor pressure of 181 mm Hg at 25°C. 
In the vapor-phase, t-butyl mercaptan will react rapidly with hydroxyl radicals with half-lives of 11.0 to 13.3 hours determined from environmental rate constants. 
An estimated Koc of 350 suggests that this compound will have moderate mobility in soil; natural gas plus t-butyl mercaptan passed through a montmorillonite clay gave 85% of the influent odorant in the effluent within the first 100 standard cubic feet of gas. 
t-Butyl mercaptan should volatilize from dry soil surfaces based on its vapor pressure. 
Given an estimated Henry’s Law constant of 6.11X10-3 atm-cu m/mole t-butyl mercaptan should volatilize from moist soil surfaces. 
In water, based on this Henry’s Law constant, t-butyl mercaptan is expected to rapidly volatilize from water surfaces; volatilization half-lives from a model river and model lake were calculated as 2.9 hours and 3.8 days, respectively. 
This compound is not expected to bioconcentrate in aquatic organisms based on an estimated BCF value of 25. 
Exposure to t-butyl mercaptan may occur occupationally during its production or during its use as a natural gas odorant. Section XII. 

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Ecological Information Ecotoxicity