Tropinone Property

Melting point:

40-44 °C(lit.)

Boiling point:

113 °C25 mm Hg(lit.)

Density 

1.0268 (rough estimate)

refractive index 

1.4598 (estimate)

Flash point:

194 °F

storage temp. 

Inert atmosphere,2-8°C

solubility 

Chloroform (Slightly), Methanol (Slightly)

pka

8.93±0.20(Predicted)

form 

crystalline

color 

brown

PH

8 (18g/l, H2O, 20℃)

BRN 

2329

InChIKey

QQXLDOJGLXJCSE-KNVOCYPGSA-N

CAS DataBase Reference

532-24-1(CAS DataBase Reference)

NIST Chemistry Reference

8-Azabicyclo[3.2.1]octan-3-one, 8-methyl-(532-24-1)

EPA Substance Registry System

8-Azabicyclo[3.2.1]octan-3-one, 8-methyl- (532-24-1)

Safety

Hazard Codes 

C,Xi

Risk Statements 

34-22-36/37/38

Safety Statements 

23-24/25-36/37/39-26-22

RIDADR 

1544

WGK Germany 

3

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

III

HS Code 

29399990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P271Use only outdoors or in a well-ventilated area.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

Tropinone Chemical Properties,Usage,Production

Description

Tropinone (8-methyl-8-azabicyclo[3.2.1]octane-3-one)(7) is the simplest plant tropane and is the first intermediate in the biosynthesis of tropane alkaloids.  Studies have called 4-(1-methyl-2-pyrrolidinyl)-3-oxobutanoic acid as an intermediate metabolite in tropinone biosynthesis[1]. It is an intermediate of atropine sulfate and is used in the synthesis of atropine. Atropine is an anticholinergic drug. It acts as an M-blocker and is indicated for the relief of visceral colic.

Chemical Properties

Tropinone is a white to light yellow crystal powder, It is an alkaloid and a precursor to a number of additional plant alkaloids. Tropinone is the first intermediate in the biosynthesis of the pharmacologically important tropane alkaloids that possesses the 8-azabicyclo[3.2.1]octane core bicyclic structure that defines this alkaloid class. Chemical synthesis of tropinone was achieved in 1901 but the mechanism of tropinone biosynthesis has remained elusive.

Uses

Tropinone is an oxidative product of Tropane, used to synthesize Morphine and Tropane alkaloids.

Preparation

The first synthesis of tropinone was by Richard Willstätter in 1901. It started from the seemingly related cycloheptanone, but required many steps and had an overall yield of only 0.75%.Willstätter had previously synthesized cocaine from tropinone, in what was the first synthesis and elucidation of the structure of cocaine.
The 1917 synthesis by Robinson is considered a legend in total synthesis due to its simplicity and biomimetic approach. Tropinone is a bicyclic molecule, but the reactants used in its preparation are fairly simple: succinaldehyde, methyl amine and acetone dicarboxylic acid (or even acetone). The synthesis is a good example of a biomimetic reaction or biogenetic-type synthesis because biosynthesis makes use of the same building blocks. It also demonstrates a tandem reaction in a one-pot synthesis. Furthermore the yield of the synthesis was 17% and with subsequent improvements exceeded 90%.

References

1. Arthur J. Birch. Investigating a Scientific Legend: The Tropinone Synthesis of Sir Robert Robinson, F.R.S. Notes and Records of the Royal Society of London, 1993, 47, 277-296. DOI:10.1098/rsnr.1993.0034
2. Andrew J. Humphrey and David O'Hagan. Tropane alkaloid biosynthesis. A century old problem unresolved. Natural Products Reports 2001, 18, 494-502. DOI:10.1039/b001713m
3. Tropinone synthesis via an atypical polyketide synthase and P450-mediated cyclization DOI:10.1038/s41467-018-07671-3
4. R. Robinson (1917). "A synthesis of tropinone". Journal of the Chemical Society, Transaction 111: 762 - 768. doi:10.1039/CT9171100762