TRANS-2,5-DIFLUOROCINNAMIC ACID

TRANS-2,5-DIFLUOROCINNAMIC ACID Property

Melting point:

138-140 °C (lit.)

Boiling point:

278.5±25.0 °C(Predicted)

Density 

1.3056 (estimate)

storage temp. 

Store at room temperature

pka

4.16±0.10(Predicted)

form 

powder

color 

Off-white

BRN 

7918450

InChI

InChI=1S/C9H6F2O2/c10-7-2-3-8(11)6(5-7)1-4-9(12)13/h1-5H,(H,12,13)/b4-1+

InChIKey

XAWHCSKPALFWBI-DAFODLJHSA-N

SMILES

C(O)(=O)/C=C/C1=CC(F)=CC=C1F

CAS DataBase Reference

112898-33-6(CAS DataBase Reference)

NIST Chemistry Reference

2,5-Difluorocinnamic acid(112898-33-6)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36-26/37/39

WGK Germany 

3

HazardClass 

IRRITANT

HS Code 

29163990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

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

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

TRANS-2,5-DIFLUOROCINNAMIC ACID Chemical Properties,Usage,Production

Chemical Properties

white crystalline powder

Uses

trans-2,5-Difluorocinnamic acid may be used in chemical synthesis.

Synthesis

The general procedure for the synthesis of trans-2,5-difluorocinnamic acid from hexahydropyridine and 2,5-difluorobenzaldehyde is as follows: 1. piperidine (2 mL, 20.2 mmol) and pyridine (50 mL) were added to a mixture of 2,5-difluorobenzaldehyde (12.07 g, 85.0 mmol) and malonic acid (18.28 g, 175.6 mmol) under stirring conditions. 2. The reaction mixture was heated to reflux (oil bath temperature 100 °C) under nitrogen protection and maintained for 2 hours. Effervescence was observed during the reaction for about 90 minutes, initially intense then gradually diminishing. 3. Upon completion of the reaction, the mixture was cooled to 20-25 °C and slowly poured into a stirred 2 M hydrochloric acid solution (310 mL) and the pH was adjusted to 1. The reaction was carried out at 20-25 °C. 4. After aging the precipitate for 1 hour at 20-25°C, it was filtered. The filter cake was washed with distilled water (2 x 50 mL) and subsequently dried for 1 hour. 5. The dried solid product was dissolved in tert-butyl methyl ether (TBME, 250 mL) to separate the organic and aqueous phases. The aqueous phase was extracted once more with TBME (100 mL). 6. The organic phases were combined, dried with magnesium sulfate (25 g), filtered and concentrated by rotary evaporator to give the white solid product trans-2,5-difluorocinnamic acid (13.4 g, 85.7% yield).

References

[1] Patent: US2003/139457, 2003, A1
[2] Patent: US2005/70578, 2005, A1