:2-Butanol

{{short description|Secondary alcohol}}

{{Chembox

| Watchedfields = changed

| verifiedrevid = 47721284

| ImageFile = 2-butanol Line-Structure.svg

| ImageFile_Ref = {{chemboximage|correct|??}}

| ImageName = Skeletal formula of 2-butanol

| PIN = Butan-2-ol{{Cite web|title = 2-butanol - Compound Summary|url = https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=6568|work = PubChem Compound|publisher = National Center for Biotechnology Information|access-date = 12 October 2011|location = USA|date = 26 March 2005|at = Identification and Related Records}}

| OtherNames = sec-Butanol{{Cite book| title = Nomenclature of Organic Chemistry (The IUPAC 'Blue Book'), Sections A, B, C, D, E, F, and H| year = 1979 | publisher = Pergamon Press | location = Oxford | chapter = Alcohols Rule C-201.1 | quote = Designations such as isopropanol, sec-butanol, and tert-butanol are incorrect because there are no hydrocarbons isopropane, sec-butane, and tert-butane to which the suffix "-ol" can be added; such names should be abandoned. Isopropyl alcohol, sec-butyl alcohol, and tert-butyl alcohol are, however, permissible (see Rule C-201.3) because the radicals isopropyl, sec-butyl, and tert-butyl do exist}}
sec-Butyl alcohol
2-Butanol
2-Butyl alcohol

| Section1 = {{Chembox Identifiers

| CASNo = 78-92-2

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

| CASNo1_Ref = {{cascite|correct|??}}

| CASNo1 = 14898-79-4

| CASNo1_Comment = (R)

| CASNo2_Ref = {{cascite|correct|??}}

| CASNo2 = 4221-99-2

| CASNo2_Comment = (S)

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

| UNII = 0TUL3ENK62

| UNII1_Ref = {{fdacite|correct|FDA}}

| UNII1 = DLH38K423J

| UNII1_Comment = (R)

| UNII2_Ref = {{fdacite|correct|FDA}}

| UNII2 = 69KXU5NDTO

| UNII2_Comment = (S)

| PubChem = 6568

| PubChem1 = 84682

| PubChem1_Comment = (R)

| PubChem2 = 444683

| PubChem2_Comment = (S)

| ChemSpiderID = 6320

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID1 = 76392

| ChemSpiderID1_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID1_Comment = (R)

| ChemSpiderID2 = 392543

| ChemSpiderID2_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID2_Comment = (S)

| EINECS = 201-158-5

| UNNumber = 1120

| DrugBank = DB02606

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| MeSHName = 2-butanol

| ChEBI = 35687

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

| ChEMBL = 45462

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| RTECS = EO1750000

| Beilstein = 773649

1718764 (R)

1718763 (S)

| Gmelin = 1686

396584 (R)

25655 (S)

| SMILES = CCC(C)O

| StdInChI = 1S/C4H10O/c1-3-4(2)5/h4-5H,3H2,1-2H3

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = BTANRVKWQNVYAZ-UHFFFAOYSA-N

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

}}

| Section2 = {{Chembox Properties

| C=4 | H=10 | O=1

| Density = 0.808 g cm⁻³

| MeltingPtK = 158

| BoilingPtK = 371 to 373

| Solubility = 390 g/L{{Cite journal|last = Alger|first = Donald B.|title = The water solubility of butan-2-ol: A widespread error|journal = Journal of Chemical Education|date=November 1991|volume = 68|issue = 11|doi = 10.1021/ed068p939.1|page = 939| bibcode=1991JChEd..68..939A }}

| VaporPressure = 1.67 kPa (at 20 °C)

| LogP = 0.683

| pKa = 17.6 Serjeant, E.P., Dempsey B.; Ionisation Constants of Organic Acids in Aqueous Solution. International Union of Pure and Applied Chemistry (IUPAC). IUPAC Chemical Data Series No. 23, 1979. New York, New York: Pergamon Press, Inc., p. 989

| RefractIndex = 1.3978 (at 20 °C)

| MagSus = {{val|-5.7683|e=-5|u=cm³ mol⁻¹}}

}}

| Section3 = {{Chembox Thermochemistry

| DeltaHf = −343.3 to −342.1 kJ mol⁻¹

| DeltaHc = −2.6611 to −2.6601 MJ mol⁻¹

| Entropy = 213.1 J K⁻¹ mol⁻¹

| HeatCapacity = 197.1 J K⁻¹ mol⁻¹

}}

| Section4 = {{Chembox Hazards

| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0112.htm inchem.org]

| GHSPictograms = {{GHS flame}} {{GHS exclamation mark}}

| GHSSignalWord = WARNING

| HPhrases = {{H-phrases|226|319|335|336}}

| PPhrases = {{P-phrases|261|305+351+338}}

| NFPA-H = 1

| NFPA-F = 3

| NFPA-R = 0

| FlashPtC = 22 to 27

| AutoignitionPtC = 405

| ExploLimits = 1.7–9.8%

| PEL = TWA 150 ppm (450 mg/m³){{PGCH|0077}}

| REL = TWA 100 ppm (305 mg/m³) ST 150 ppm (455 mg/m³)

| IDLH = 2000 ppm

| LCLo = 16,000 ppm (rat, 4 hr)
10,670 ppm (mouse, 3.75 hr)
16,000 ppm (mouse, 2.67 hr)

}}

| Section5 = {{Chembox Related

| OtherFunction_label = butanols

| OtherFunction = n-Butanol
Isobutanol
tert-Butanol

| OtherCompounds = Butanone

}}

}}

Butan-2-ol, or sec-butanol, is an organic compound with formula CH₃CH(OH)CH₂CH₃. Its structural isomers are 1-butanol, isobutanol, and tert-butanol. 2-Butanol is chiral and thus can be obtained as either of two stereoisomers designated as (R)-(−)-butan-2-ol and (S)-(+)-butan-2-ol. It is normally encountered as a 1:1 mixture of the two stereoisomers — a racemic mixture.

This secondary alcohol is a flammable, colorless liquid that is soluble in three parts water and completely miscible with organic solvents. It is produced on a large scale, primarily as a precursor to the industrial solvent methyl ethyl ketone.

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(R)-(−)-2-butanol	(S)-(+)-2-butanol