Acetone imine, or 2-propanimine is an organic compound and an imine with the chemical formula (CH3)2CNH. It is a volatile and flammable liquid at room temperature. It is the simplest ketimine. This compound is mainly of academic interest.

Acetone imine
Full structural formula of acetone imine with dimensions
Full structural formula of acetone imine with dimensions
Skeletal formula of acetone imine
Skeletal formula of acetone imine
Ball-and-stick model of acetone imine
Ball-and-stick model of acetone imine
Space-filling model of acetone imine
Space-filling model of acetone imine
Names
Preferred IUPAC name
Propan-2-imine[1]
Other names
  • Acetone imine
  • 2-Propanimine
Identifiers
3D model (JSmol)
ChemSpider
MeSH Imine Acetone Imine
  • InChI=1S/C3H7N/c1-3(2)4/h4H,1-2H3
    Key: XDAGXZXKTKRFMT-UHFFFAOYSA-N
  • CC(=N)C
Properties
C3H7N
Molar mass 57.096 g·mol−1
Appearance colorless liquid
Density 0.8 g cm−3 (25 °C)
Boiling point 57–59 °C (135–138 °F; 330–332 K)
log P -0.56
1.394
Hazards
GHS labelling:
GHS02: Flammable GHS07: Exclamation mark
Danger
H225, H319, H336
P210, P261, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
0
3
0
Flash point 14.7 °C (58.5 °F; 287.8 K)
Related compounds
Related compounds
Acetone oxime
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Synthesis and reactions

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Acetone imine is prepared by dehydrocyanation of the cyanoamine of acetone, which is prepared from acetone cyanohydrin. Dicyclohexylcarbodiimide (CyN=C=NCy) serves as the scavenger for hydrogen cyanide:[2]

(CH3)2C(NH2)CN + CyN=C=NCy → (CH3)2CNH + CyN(H)-C(CN)=NCy
 
Upon standing at room temperature, samples of acetone imine degrade to give this heterocycle, called acetonin.

The compound hydrolyzes readily:

(CH3)2CNH + H2O → (CH3)2CO + NH3

This reactivity is characteristic of imines derived from ammonia. Methylene imine (CH2=NH) is also highly reactive, condensing to hexamethylenetetramine. Upon standing, acetone imine undergoes further condensation to give the tetrahydropyrimidine called acetonin, with loss of ammonia.[3]

The imine of hexafluoroacetone, ((CF3)2C=NH) is by contrast robust.[4]

References

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  1. ^ "Synonyms". Pubchem.
  2. ^ K. Findeisen; H. Heitzer; K. Dehnicke (1981). "Neue Methode zur Herstellung von Aldiminen und Ketiminen". Synthesis. 1981 (9): 702–704. doi:10.1055/s-1981-29566. S2CID 98811861.
  3. ^ Matter, E. (1947). "Über ein neues Reaktionsprodukt aus Aceton und Ammoniak (Acetonin) (A new reaction product from acetone and ammonia (acetonine)) I". Helvetica Chimica Acta. 30: 1114–23. doi:10.1002/hlca.19470300503.
  4. ^ W. J. Middleton, H. D. Carlson (1970). "Hexafluoroacetone Imine". Org. Syntheses. 50: 81–3. doi:10.15227/orgsyn.050.0081..