Butynone

Butynone
Names
	IUPAC name But-3-yn-2-one
	Other names Butyn-2-one; Acetylacetylene; Methyl ethynyl ketone; Acetylethyne;
Identifiers
CAS Number	1423-60-5;
3D model (JSmol)	Interactive image;
Beilstein Reference	605353
ChEBI	CHEBI:48060;
ChemSpider	14294;
ECHA InfoCard	100.014.395
EC Number	215-834-2;
Gmelin Reference	49292
PubChem CID	15018;
UNII	ST682FTU47;
CompTox Dashboard (EPA)	DTXSID3074521 ;
	InChI InChI=1S/C4H4O/c1-3-4(2)5/h1H,2H3 Key: XRGPFNGLRSIPSA-UHFFFAOYSA-N;
	SMILES CC(=O)C#C;
Properties
Chemical formula	HC2COCH3
Molar mass	116.072 g·mol−1
Boiling point	85 °C (185 °F; 358 K)
Hazards
	GHS labelling:
Pictograms	‍‍
Signal word	Danger
Hazard statements	H225, H300, H315, H319, H335
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+P310+P330, P303+P361+P353, P304+P340+P312, P305+P351+P338, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
Safety data sheet (SDS)	Sigma-Aldrich Co., product no. 161314.
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Butynone is an organic compound and the simplest ynone. It is a reagent used in organic synthesis as a dienophile and Michael acceptor.

Preparation

The triisopropylsilyl derivative of butynone is prepared by oxidation of the corresponding derivative of 2-butynol, itself prepared from TIPS acetylene by deprotonation followed by nucleophilic addition to acetaldehyde.^[1]

Butynone was one of the reagents used in the discovery of the Bohlmann–Rahtz pyridine synthesis.^[2]

Butynone and its derivatives participate in cycloaddition reactions, yielding a variety of heterocycles. The electron-deficient alkyne group participates in the azide-alkyne Huisgen cycloaddition to produce 1,2,3-triazine methyl ketones.^[3] [4+2+1] cycloaddition with 1,2-phenylenediamine and furfural derivatives gives benzodiazepine rings.^[4]

^ James A. Marshall, Patrick Eidam, and Hilary Schenck Eidam (2008). "Synthesis of 4-triisopropylsilyl-3-butyn-2-ol by asymmetric transfer hydrogenation". Organic Syntheses. 84: 120{{cite journal}}: CS1 maint: multiple names: authors list (link).
^ Bagley, Mark; Glover, Christian; Merritt, Eleanor (2007). "The Bohlmann-Rahtz Pyridine Synthesis: From Discovery to Applications". Synlett (16): 2459–2482. doi:10.1055/s-2007-986674.
^ Bakka, Thomas A.; Strøm, Morten B.; Andersen, Jeanette H.; Gautun, Odd R. (2017). "Methyl propiolate and 3-butynone: Starting points for synthesis of amphiphilic 1,2,3-triazole peptidomimetics for antimicrobial evaluation". Bioorganic & Medicinal Chemistry. 25 (20): 5380–5395. doi:10.1016/j.bmc.2017.07.060. hdl:10037/11419. PMID 28797773.
^ Jiang, Jingjing; Queneau, Yves; Popowycz, Florence (2023). "Ammonium Acetate Catalyzed Formation of 1,5-Benzodiazepines through [4+2+1] Cycloaddition Involving 5-Hydroxymethylfurfural". European Journal of Organic Chemistry. 26 (19) e202300144. doi:10.1002/ejoc.202300144.