P-Dimethylaminocinnamaldehyde

p-Dimethylaminocinnamaldehyde (DMACA) is an aromatic hydrocarbon. It is used in an acidic solution to detect indoles.

p-Dimethylaminocinnamaldehyde

Names
IUPAC name 3-[4-(Dimethylamino)phenyl]prop-2-enal
Other names DMAC 4-Dimethylaminocinnamaldehyde
Identifiers
CAS Number	20432-35-3 Y
3D model (JSmol)	Interactive image
Abbreviations	DMACA
Beilstein Reference	972369
ChemSpider	4447567 (E) 23646677 (Z) 83262
EC Number	228-267-0
MeSH	4-Dimethylaminocinnamaldehyde
PubChem CID	5284506 (E) 25310830 (Z) 92224
UNII	9RSI7WZ9F0 Y
CompTox Dashboard (EPA)	DTXSID9022237
InChI InChI=1S/C11H13NO/c1-12(2)11-7-5-10(6-8-11)4-3-9-13/h3-9H,1-2H3/b4-3+ Key: RUKJCCIJLIMGEP-ONEGZZNKSA-N InChI=1/C11H13NO/c1-12(2)11-7-5-10(6-8-11)4-3-9-13/h3-9H,1-2H3/b4-3+ Key: RUKJCCIJLIMGEP-ONEGZZNKBZ
SMILES [H]C(=O)C=CC1=CC=C(C=C1)N(C)C
Properties
Chemical formula	C11H13NO
Molar mass	175.22 g/mol
Appearance	white to light yellow crystal powder
Density	1.057 g/mL
Melting point	138 °C (280 °F; 411 K)
Boiling point	329 °C (624 °F; 602 K)
Solubility in dioxane	50 g/L
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Use as a testing reagent

The DMACA is any of a number of acidified DMACA solutions:

• 0.117 g of DMACA, 39 mL of ethanol, 5 mL of conc hydrochloric acid and diluted to 50mL with water^[1]
• 1 g DMACA, 1 mL conc. hydrochloric acid and 99 mL water^[2]
• 1 g DMACA in 99 mL conc. hydrochloric acid.^[3]

It is primarily used as a histological dye used to detect indoles, particularly for production in cells. It is used for the rapid identification of bacteria containing tryptophanase enzyme systems.^{[citation needed]} It is also particularly useful for localization of proanthocyanidins compounds in plants, resulting in a blue staining. It has been used for grapevine fruit^[4] or for legumes foliage^[5] histology.

A colorimetric assay based upon the reaction of A-rings^{[clarification needed]} with the chromogen. p-Dimethylaminocinnamaldehyde has been developed for flavanoids in beer that can be compared with the vanillin procedure.^[6] The DMACA reagent may be superior to the vanillin procedure for the detection of catechins.^[7]

The DMACA reagent changes color over several days when exposed to air but when refrigerated can be stored for up to two weeks.^[8]

The DMACA reagent may also be referred to as the Renz and Loew reagent.^[3][9]

See also

• Ehrlich's reagent, a simple spot-test to presumptively identify alkaloids