4-hydroxybenzoic acid butyl ester

Structural formula
General
Surname	4-hydroxybenzoic acid butyl ester
other names	p -Hydroxybenzoic acid butyl ester; PHB butyl ester; Butyl 4-hydroxybenzoate ( IUPAC ); Butyl para- hydroxybenzoate; BUTYLPARABEN ( INCI ) ;
Molecular formula	C 11 H 14 O 3
Brief description	colorless, crystalline powder
External identifiers / databases
EC number	202-318-7
ECHA InfoCard	100.002.108
PubChem	7184
ChemSpider	6916
DrugBank	DB14084
Wikidata	Q3302873
properties
Molar mass	194.22 g · mol -1
Physical state	firmly
density	1.23 g cm −3 (20 ° C)
Melting point	68-69 ° C
Vapor pressure	3.88 · 10 −2 Pa (50 ° C)
solubility	slightly soluble in water (0.2 g l −1 at 20 ° C); Methanol , ethanol , acetone , propylene glycol , diethyl ether ;
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
Authorization procedure under REACH	Of particular concern: Serious effects on human health are considered likely
Toxicological data	13200 mg kg −1 ( LD 50 , mouse , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

4-Hydroxybenzoic acid butyl ester is the butyl ester of the aromatic carboxylic acid 4-hydroxybenzoic acid and belongs to the parabens .

Manufacturing

The compound is synthesized by esterifying 4-hydroxybenzoic acid with n- butanol . Another variant is the transesterification of methyl paraben with n -butanol.

properties

4-Hydroxybenzoic acid butyl ester is a colorless crystalline substance. The melting point is 68.6 ° C with a melting enthalpy of 137.2 J · g ⁻¹ . The compound crystallizes in a monoclinic crystal lattice with the space group C2 / c . According to August, the vapor pressure function results from ln (P) = −A / T + B (P in Pa, T in K) with A = 37.1 ± 0.2 and B = 13042 ± 100 in the temperature range from 47 ° C to 60 ° C. A molar enthalpy of sublimation of 108.4 kJ · mol ⁻¹ can be derived from the vapor pressure function . The solubility in water is low, in organic solvents it is rather very good.

Solubility in various solvents (at 25 ° C, in g / 100 g solvent)
solvent	water	Water (80 ° C)	Methanol	Ethanol	Propylene glycol	acetone	Diethyl ether	peanut oil
solubility	0.02	0.15	220	210	110	240	150	5.0

The 4-hydroxybenzoic acid butyl ester forms eutectically melting mixtures with other 4-hydroxybenzoic acid esters .

Eutectics for mixtures of 4-hydroxybenzoic acid esters
	Methyl paraben	Ethyl paraben	Propyl paraben
Mole fraction of butyl paraben	0.22	0.76	0.67
Eutectic melting point	59.8 ° C	58.3 ° C	54.6 ° C

use

Like all parabens, the compound can be used as a preservative in food as well as pharmaceutical and cosmetic products.

Individual evidence

↑ Entry on BUTYLPARABEN in the CosIng database of the EU Commission, accessed on June 3, 2020.
↑ ^a ^b ^c ^d ^e ^f Entry for CAS no. 94-26-8 in the GESTIS substance database of the IFA , accessed on July 9, 2016(JavaScript required) .
↑ ^a ^b ^c ^d ^e Giordano, F .; Bettini, R .; Donini, C .; Gazzaniga, A .; Caira, MR; Zhang, GGZ; Grant, DJW: Physical properties of parabens and their mixtures: Solubility in water, thermal behavior, and crystal structures , in J. Pharm. Sci. 88 (1999) 1210-1216, doi : 10.1021 / js9900452 .
↑ ^a ^b ^c ^d ^e Entry on 4-hydroxybenzoates. In: Römpp Online . Georg Thieme Verlag, accessed on July 10, 2016.
↑ ^a ^b ^c Perlovich, GL; Rodionov, SV; Bauer-Brandl, A .: Thermodynamics of solubility, sublimation and solvation processes of parabens , in Eur. J. Pharm. Sci. 24 (2005) 25-33, doi : 10.1016 / j.ejps.2004.09.007 .
↑ Entry in the SVHC list of the European Chemicals Agency , accessed on June 26, 2020.
↑ Entry on butyl 4-hydroxybenzoate in the ChemIDplus database of the United States National Library of Medicine (NLM) .
↑ Inouye, Masahiko; Chiba, Junya; Nakazumi, Hiroyuki: Glucopyranoside Recognition by Polypyridine-Macrocyclic Receptors Possessing a Wide Cavity with a Flexible Linkage , in J. Org. Chem. 64 (1999) 8170-8176, doi : 10.1021 / jo9911138 .
↑ Iwasaki, Takanori; Maegawa, Yusuke; Hayashi, Yukiko; Ohshima, Takashi; Mashima, Kazushi: Transesterification of Various Methyl Esters Under Mild Conditions Catalyzed by Tetranuclear Zinc Cluster , in J. Org. Chem. 73 (2008) 5147-5150, doi : 10.1021 / jo800625v .

[CosIng-1] Entry on BUTYLPARABEN in the CosIng database of the EU Commission, accessed on June 3, 2020.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f Entry for CAS no. 94-26-8 in the GESTIS substance database of the IFA , accessed on July 9, 2016(JavaScript required) .

[Grant-3] Giordano, F .; Bettini, R .; Donini, C .; Gazzaniga, A .; Caira, MR; Zhang, GGZ; Grant, DJW: Physical properties of parabens and their mixtures: Solubility in water, thermal behavior, and crystal structures , in J. Pharm. Sci. 88 (1999) 1210-1216, doi : 10.1021 / js9900452 .

[Römpp-4] Entry on 4-hydroxybenzoates. In: Römpp Online . Georg Thieme Verlag, accessed on July 10, 2016.

[Perlovich-5] Perlovich, GL; Rodionov, SV; Bauer-Brandl, A .: Thermodynamics of solubility, sublimation and solvation processes of parabens , in Eur. J. Pharm. Sci. 24 (2005) 25-33, doi : 10.1016 / j.ejps.2004.09.007 .

[SVHC-6] Entry in the SVHC list of the European Chemicals Agency , accessed on June 26, 2020.

[ChemIDplus-7] Entry on butyl 4-hydroxybenzoate in the ChemIDplus database of the United States National Library of Medicine (NLM) .

[8] Inouye, Masahiko; Chiba, Junya; Nakazumi, Hiroyuki: Glucopyranoside Recognition by Polypyridine-Macrocyclic Receptors Possessing a Wide Cavity with a Flexible Linkage , in J. Org. Chem. 64 (1999) 8170-8176, doi : 10.1021 / jo9911138 .

[9] Iwasaki, Takanori; Maegawa, Yusuke; Hayashi, Yukiko; Ohshima, Takashi; Mashima, Kazushi: Transesterification of Various Methyl Esters Under Mild Conditions Catalyzed by Tetranuclear Zinc Cluster , in J. Org. Chem. 73 (2008) 5147-5150, doi : 10.1021 / jo800625v .