Cinnamic Acid

Product Name:

Cinnamic acid

Synonyms:

high purity Cinnamic acid kf-wang(at)kf-chem.com;CitricAcidGr(Monohydrate);CinnamonAcid;Benzenepropenoic acid;3-Phenylpropenoic;CINNAMIC ACID, TRANS-(SH);ZIMTSAEURE ERG.B.6;Phenylacrylic acid

CAS:

621-82-9

MF:

C9H8O2

MW:

148.16

EINECS:

210-708-3

Product Categories:

Mol File:

621-82-9.mol

Melting point 

133 °C(lit.)

Boiling point 

300 °C(lit.)

density 

1.2475

FEMA 

2288 | CINNAMIC ACID

refractive index 

1.5049 (estimate)

Fp 

>230 °F

pka

pK (25°) 4.46

Water Solubility 

511.2mg/L(25 ºC)

JECFA Number

657

Stability:

Stable. Combustible. Incompatible with strong oxidizing agents.

CAS DataBase Reference

621-82-9(CAS DataBase Reference)

NIST Chemistry Reference

2-Propenoic acid, 3-phenyl-(621-82-9)

EPA Substance Registry System

Cinnamic acid (621-82-9)

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

1

RTECS 

GD7850000

Toxicity

LD50 (g/kg): 3.57 orally in rats; >5.0 dermally in rabbits (Letizia)

Content Analysis

Accurately weigh 500 mg of sample which have been previously dried for 3 hours in drier filled with silica gel; add 0.1mol/L hydrogen.

Toxicity

GRAS (FEMA). 
LD50 2500 mg/kg (rat, oral)

Limited use

FEMA (mg/kg): Soft drinks 31; Cold drink 40; Confectionery 30; Bakery 36; Gum 10. 
Take moderate as the limit (FDA§172.515, 2000).

Chemical Properties

It appears as white monoclinic prisms with slight cinnamon aroma. It is soluble in ethanol, methanol, petroleum ether and chloroform; it is easily soluble in benzene, ether, acetone, acetic acid, carbon disulfide and oils but insoluble in water.

Uses

1. It can be used as raw materials for the manufacturing of ester, spices and pharmaceuticals. 
2. It can be used for chemical reagents as well as being used for the synthetic of perfume and pharmaceutical. 
3. GB 2760-96 provides it for allowable edible flavors. It is mainly used for the preparation of spices and cherries, apricots, honey flavor. It can also applied to the anti-corrosion protection of fresh fruits and vegetables.

Production method

1. It can be obtained through the co-heating reaction between benzyl chloride and sodium acetate. 
2. It can also be generated through the co-heating reaction between benzaldehyde and sodium acetate (or potassium acetate) in the presence of a dehydrogenating agent. 
3. It can also be prepared through: mixing the benzoylacetone, sodium carbonate and bleach, generating sodium cinnamic acid, followed by processing with sulfate.

Chemical Properties

monoclinic crystals

Chemical Properties

Cinnamic acid is almost odorless with a burning taste, and then turning sweet and reminiscent of apricot.

Preparation

Two isomers, trans- and cis- exist; the trans-isomer is of interest for use in flavoring; in addition to the extraction from natural sources (storax), it can be prepared as follows: (1) from benzaldehyde, anhydrous sodium acetate and acetic anhydride in the presence of pyridine (Perkin reaction); (2) from benzaldehyde and ethyl acetate (Claisen condensation); (3) from benzaldehyde and acetylene chloride; (4) by oxidation of benzylidene acetone with sodium hypochlorite.

Safety Profile

Poison by intravenous and intraperitoneal routes. Moderately toxic by ingestion. A skin irritant. Combustible liquid. When heated to decomposition it emits acrid smoke and fumes.

Chemical Synthesis

Rainer Ludwig Claisen (1851–1930), German chemist, described for the first time in 1890 the synthesis of cinnamates by reacting aromatic aldehydes with esters. The reaction is known as the Claisen condensation.

Purification Methods

Crystallise the acid from *benzene, CCl4, hot water, water/EtOH (3:1), or 20% aqueous EtOH. Dry it at 60o in vacuo. It is steam volatile. [Beilstein 9 IV 2002.]

Raw materials

Benzyl chloride-->Sodium acetate trihydrate-->Potassium Acetate-->Calcium hypochlorite-->trans-Cinnamic acid-->Benzalacetone

Preparation Products

L-Phenylalanine-->2-[3-[Bis(1-methylethyl)amino]-1-phenylpropyl]-4-methylphenol-->L-PHENYLALANINE