Emboxylic acid

Structural formula
General
Surname	Emboxylic acid
other names	4,4′-methylenebis (3-hydroxy-2-naphthoic acid) ( IUPAC ); Pamoic acid;
Molecular formula	C 23 H 16 O 6
Brief description	yellow needles
External identifiers / databases
EC number	204-998-0
ECHA InfoCard	100.004.545
PubChem	8546
Wikidata	Q411413
properties
Molar mass	388.38 g mol −1
Physical state	firmly
Melting point	≥ 300 ° C (decomposition)
pK s value	pK s 1 = 2.51; pK s 2 = 3.1;
solubility	almost insoluble in water, ethanol or diethyl ether ; soluble in nitrobenzene and pyridine ;
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315-319-335
	P: 261-305 + 351 + 338
Toxicological data	390 mg kg −1 ( LD 50 , mouse , ip )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Emboxylic acid or pamoic acid is a derivative of naphthalene-2-carboxylic acid ( 2-naphthoic acid ). It arises from the reaction of 3-hydroxy-2-naphthoic acid with formaldehyde . The salts of emboxylic acid are known as embonates or pamoates.

use

Emboxylic acid usually forms very sparingly soluble salts with basic medicinal products, from which the active ingredient is only slowly released. Such embonates are therefore used in pharmacy as depot medicament forms .

Origin of name

The term e mb o n acid is an abbreviation of the chemical name 4,4 M ethylene b is (3-hydroxy-2- n aphthoesäure). The origin of the name pamoic acid is not entirely certain. It is probably derived from the anti- malarial drug pamaquin . This was the first liquid base to be used as a solid pamoate.

Individual evidence

↑ ^a ^b ^c Entry on Embonsäure. In: Römpp Online . Georg Thieme Verlag, accessed on June 14, 2014.
↑ ^a ^b ^c data sheet Pamoic acid from Sigma-Aldrich , accessed on March 30, 2011 ( PDF ).
^ ^A ^b ^c P. Heinrich Stahl: Pharmaceutical Salts. Wiley, 2002, ISBN 978-3-906-39026-0 , p. 335 ( limited preview in Google book search).
^ ^A ^b Alexander Senning: Elsevier's Dictionary of Chemoetymology. Elsevier, 2006, ISBN 978-0-080-48881-3 , p. 292 ( limited preview in Google book search).

[Römpp-1] Entry on Embonsäure. In: Römpp Online . Georg Thieme Verlag, accessed on June 14, 2014.

[Sigma-2] ta sheet Pamoic acid from Sigma-Aldrich , accessed on March 30, 2011 ( PDF ).

[googlebooks1-3] A ^b ^c P. Heinrich Stahl: Pharmaceutical Salts. Wiley, 2002, ISBN 978-3-906-39026-0 , p. 335 ( limited preview in Google book search).

[googlebooks2-4] A ^b Alexander Senning: Elsevier's Dictionary of Chemoetymology. Elsevier, 2006, ISBN 978-0-080-48881-3 , p. 292 ( limited preview in Google book search).