75-33-2

Basic information

• Product Name: 2-Propanethiol
• Synonyms: iso-C3H7SH;Isopropylthiol;mercaptanisopropylique;Propanethiol-(2);FEMA 3897;IPM(TM);ISOPROPYL MERCAPTAN;Isopropanethiol
• CAS NO: 75-33-2
• Molecular Formula: C₃H₈S
• Molecular Weight: 76.16
• EINECS: 200-861-4
• Product Categories: thiol Flavor
• Mol File: 75-33-2.mol
• Article Data: 13

Chemical Properties

• Melting Point: −131 °C(lit.)
• Boiling Point: 57-60 °C(lit.)
• Flash Point: <−30 °F
• Appearance: Colorless/Liquid
• Density: 0.82 g/mL at 25 °C(lit.)
• Vapor Density: 2.6 (vs air)
• Vapor Pressure: 455 mm Hg ( 37.8 °C)
• Refractive Index: n20/D 1.426(lit.)
• Storage Temp.: Flammables area
• PKA: pK1:10.86 (25°C,μ=0.1)
• Water Solubility: Slightly soluble in water
• Sensitive: Air Sensitive
• Stability: Stable. Highly flammable - note low flashpoint. May form explosive mixtures with air.
• BRN: 605260
• CAS DataBase Reference: 2-Propanethiol(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Propanethiol(75-33-2)
• EPA Substance Registry System: 2-Propanethiol(75-33-2)

Safety Data

• Hazard Codes: F,Xi
• Statements: 11-36/37/38-36/38
• Safety Statements: 16-26-9-37/39-33
• RIDADR: UN 2402 3/PG 2
• WGK Germany: 3
• RTECS: TZ7302000
• F: 13
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 75-33-2(Hazardous Substances Data)

Usage

Description

2-Propanethiol, also known as Isopropyl mercaptan, is an alkanethiol that is propane substituted by a sulfanyl group at position 2. It is a volatile sulfur compound with a strong skunk-like odor and is a white liquid with an exceedingly unpleasant smell.

Uses

Used in Chemical Industry:
2-Propanethiol is used as an intermediate for the preparation of polyol block copolymer, which is a type of polymer with a wide range of applications in various industries.
Used in Petroleum Industry:
2-Propanethiol is used as a standard for petroleum analysis, helping to ensure the quality and purity of petroleum products.
Used in Natural Gas Industry:
2-Propanethiol is used as a natural gas odorant, providing a distinct smell to natural gas, which aids in the detection of leaks and ensures safety.
Occurrence:
2-Propanethiol is reported to occur in irradiated beef, where it may be produced as a result of the irradiation process.

Preparation

2-Propanethiol is synthesised by the reaction of sodium hydrosulfide and brominated isopropane.

Air & Water Reactions

Highly flammable. Soluble in water.

Reactivity Profile

2-Propanethiol is incompatible with acids, diazo and azo compounds, halocarbons, isocyanates, aldehydes, alkali metals, nitrides, hydrides, and other strong reducing agents. Reactions with these materials generate heat and in many cases hydrogen gas. May liberate hydrogen sulfide when mixed with an acid.

Hazard

Highly flammable, dangerous fire hazard.

Health Hazard

Inhalation causes loss of sense of smell, muscular weakness, convulsions, respiratory paralysis. Ingestion causes nausea and vomiting. Contact with eyes or skin causes irritation.

Purification Methods

Purify it as for propane-1-thiol above. [Beilstein 1 IV 1498.]

InChI:InChI=1/C3H8S/c1-3(2)4/h3-4H,1-2H3

Synthetic route

diisopropyl sulfide (4253-89-8) + propionaldehyde (123-38-6) → S-isopropyl thiol-propionate (2432-47-5) + 2-propanethiol (75-33-2)

Conditions	Yield
at 5℃; for 4h; Irradiation;	A 40% B 40%

Zn(2+)*2SC3H7(1-) = Zn(SC3H7)2 → propene (187737-37-7) + diisopropyl sulfide (4253-89-8) + zinc sulfide + 2-propanethiol (75-33-2)

Conditions	Yield
In neat (no solvent) under vac.,heated at 260 °C, 8 h,; GC;	A 8% B 22% C n/a D 17%

hexamethyl-[1,3,5]trithiane (828-26-2) → 2-propanethiol (75-33-2)

Conditions	Yield
at 215℃;

2-iodo-propane (75-30-9) → 2-propanethiol (75-33-2)

Conditions	Yield
With ethanol; water; potassium hydrosulfide

2-iodo-propane (75-30-9) → diisopropylsulfide (625-80-9) + 2-propanethiol (75-33-2)

Conditions	Yield
With ethanol; potassium hydrosulfide

propene (187737-37-7) + diethyltetrasulfane (13730-34-2) → diisopropylsulfide (625-80-9) + Prop-1-en-1-thiol (925-89-3) + 2-propanethiol (75-33-2)

Conditions	Yield
at 180℃;

propene (187737-37-7) → 1,2-dithiole-3-thione (534-25-8) + 2-propanethiol (75-33-2)

Conditions	Yield
With sulfur at 240℃;

propene (187737-37-7) → 2-propanethiol (75-33-2)

Conditions	Yield
With sulfur
With hydrogen sulfide
With hydrogen sulfide; sulfur
With hydrogen sulfide at 200℃; under 1875.19 Torr; Temperature; Pressure;

propene (187737-37-7) → 1-thiopropane (107-03-9) + 2-propanethiol (75-33-2)

Conditions	Yield
With kieselguhr; nickel(II) sulfide; hydrogen sulfide at 250 - 300℃;
With kieselguhr; nickel(II) sulfide; hydrogen sulfide at 250 - 300℃;

diisopropyl sulfide (4253-89-8) → 2-propanethiol (75-33-2)

Conditions	Yield
With acetic acid; zinc
With diethyl ether; sodium
With phosphite radicals In water Rate constant; Mechanism; Irradiation;

propylene sulphide (1072-43-1) → 2-propanethiol (75-33-2)

Conditions	Yield
With lithium aluminium tetrahydride; diethyl ether

thiourea (17356-08-0) + isopropyl bromide (75-26-3) → 2-propanethiol (75-33-2)

Conditions	Yield
With water anschliessende Verseifung mit KOH;

isopropyl alcohol (67-63-0) → 2-propanethiol (75-33-2)

Conditions	Yield
With phosphorous (V) sulfide Erhitzen des erhaltenen Dithiophosphorsaeure-O,O'-diisopropylesters auf 160grad;
With hydrogen sulfide; thorium dioxide at 300 - 360℃;

acetone (67-64-1) → 2-propanethiol (75-33-2)

Conditions	Yield
With cobalt polysulfide; sulfur; acetic acid at 150 - 200℃; under 77228.3 - 102971 Torr; Hydrogenation;

isopropyl bromide (75-26-3) → 2-propanethiol (75-33-2)

Conditions	Yield
With ethanol; potassium hydrosulfide
With sodium hydrogensulfide; ethanol

propene (187737-37-7) → 1-thiopropane (107-03-9) + propyl sulfide (111-47-7) + n-propyl isopropyl sulfide (5008-73-1) + 2-propanethiol (75-33-2)

Conditions	Yield
With benzophenone; hydrogen sulfide; phosphorous acid trimethyl ester In diethylene glycol dimethyl ether at 10℃; for 4h; Product distribution; Irradiation; variation of reagents and solvents (t. butanol, benzene);

3,3,4,4-tetramethyl-1,2-oxathietane (102505-81-7) → 2,3-dimethyl-2-mercapto-3-butanol (52267-30-8) + 2-propanethiol (75-33-2) + isopropyl alcohol (67-63-0)

Conditions	Yield
With lithium aluminium tetrahydride In diethyl ether for 1h; Heating;	A 8 % Chromat. B 24 % Chromat. C 68 % Chromat.

S-nitroso-2-propanethiol (69165-81-7) + N-Acetylcysteine (7218-04-4, 26117-28-2, 616-91-1) → 2-propanethiol (75-33-2) + 2-hydroxyethanethiol (60-24-2)

Conditions	Yield
With sodium hydroxide In 1,4-dioxane at 25℃; Rate constant; pH 7.4;

diisopropylsulfide (625-80-9) → 2-propanethiol (75-33-2)

Conditions	Yield
With hydrogen In acetone at -78℃; under 4 Torr; Mechanism; other alkyl sulfides and alkyl substituted-benzyl sulfides, competition with n-propyl sulfide, reaction rate relative to n-propyl sulfide, microwave generation of H from H2;

tetramethyl-[1,3]dithietane (31443-08-0) + sodium amalgam → 2-propanethiol (75-33-2)

acetic acid (64-19-7) + acetone (67-64-1) + sulfur + hydrogen + cobalt sulfide-catalyst → 2-propanethiol (75-33-2)

Conditions	Yield
at 150 - 200℃; under 77228.3 - 102971 Torr;

acetic acid (64-19-7) + acetone (67-64-1) + sulfur + hydrogen + nickel sulfide-catalyst → 2-propanethiol (75-33-2)

Conditions	Yield
at 150 - 200℃; under 77228.3 - 102971 Torr;

Upstream product

• 828-26-2 hexamethyl-[1,3,5]trithiane 
• 75-30-9 2-iodo-propane 
• 187737-37-7 propene 
• 13730-34-2 diethyltetrasulfane 
• 1072-43-1 propylene sulphide 
• 17356-08-0 thiourea 
• 75-26-3 isopropyl bromide 
• 67-63-0 isopropyl alcohol 
• 102505-81-7 3,3,4,4-tetramethyl-1,2-oxathietane 
• 69165-81-7 S-nitroso-2-propanethiol 
• 7218-04-4 N-Acetylcysteine 
• 625-80-9 diisopropylsulfide 
• 31443-08-0 tetramethyl-[1,3]dithietane 
• 60-29-7 diethyl ether 

Downstream Products

• 10129-32-5 (2-chloro-phenyl)-thiocarbamic acid S-isopropyl ester 
• 10129-28-9 phenyl-thiocarbamic acid S-iso-propyl ester 
• 5443-87-8 6-isopropylmercapto-7(9)H-purine 
• 926-73-8 2-acetylsulfanyl-propane 
• 13889-93-5 S-isopropyl chlorothiocarbonate 
• 7309-43-5 1-isopropylsulfanyl-butane 
• 33672-51-4 2-isopropyldisulfanylpropane 
• 6301-46-8 D-erythro-2-deoxy-pentose-diisopropyldithioacetal 
• 120023-97-4 ethyl-thiophosphonic acid S-isopropyl ester-O-(4-nitro-phenyl ester) 
• 320-15-0 isopropyl-(2,4,6-tris-trifluoromethyl-phenyl)-sulfide 
• 6631-70-5 N-ethyl-N-(propan-2-ylsulfanylmethyl)ethanamine 
• 53584-04-6 3-(2-propylmercapto)propionitrile 
• 112988-41-7 isopropylsulfanyl-acetone 
• 5402-70-0 β-isopropylsulfanyl-isobutyric acid methyl ester 

Relevant articles and documents

A process for the preparation of isoflavones propanethiol

The invention discloses a method for synthesizing isopropyl mercaptan from propylene and hydrogen sulfide. According to the method, a heat insulation type fixed bed reactor is used and isopropyl mercaptan is synthesized of hydrogen sulfide and propylene in the presence of a solid acid catalyst according to a continuous production process. The method disclosed by the invention has the advantages that the reaction conditions are easy to control, the yield is high, the process is simple, and the environmental pollution is reduced.

Mechanism of the Solution-Phase Reaction of Alkyl Sulfides Atomic Hydrogen. Reduction via a 9-S-3 Radical Intermediate

The low selectivity of benzyl alkyl sulfide fragmentation subsequent to its reaction with atomic hydrogen is indicative of a reaction that proceeds via an early transition state. The competitive reduction of a series of substituted-benzyl alkyl sulfides was insensitive to the substituent on the aromatic ring (ρ = -0.13, r = 0.99). The relative rates of fragmentation of a series of the substituted-benzyl alkyl sulfides gave a V-shaped Hammett plot. Both electron-donating and electron-withdrawing groups destabilized the transition state (ρ = +0.99, r = 0.999; ρ = -0.82, r = 0.992). Since the relative rates of disappearance of the alkyl benzyl sulfides are not substituent dependent, but the relative rates of fragmentation are, a 9-S-3 intermediate is preferred as the structure leading to products.

NO-Group transfer (transnitrosation) between S-nitrosothiols and thiols. Part 2

The kinetics of NO-group transfer have been measured for the reaction between a nitrosothiol (HOCH2CH2SNO) and nine thiols, mostly based on the cysteine structure.The reaction is second-order and there is evidence for a steric effect for thiols containing 1,1-dimethyl substituents (penicillamine derivatives).Reaction occurs via the thiolate anion as shown by the pH-rate constant profile, and a full kinetic analysis for the reactions of two thiols (N-acetylcysteine and glutathione) is quantitatively in agreement with this mechanism.Variation of the nitrosothiol structure for reaction with N-acetylcysteine shows that electron-withdrawing substituents in the nitrosothiol promote reaction; there is a similarity with the corresponding reactions of alkyl nitrites.