1,3-dichloro-2-propanol

Structural formula
General
Surname	1,3-dichloro-2-propanol
other names	1,3-dichloropropan-2-ol 1,3-dichlorohydrin Glycerol-α, γ-dichlorohydrin 1,3-DCP
Molecular formula	C 3 H 6 Cl 2 O
Brief description	colorless liquid with a phenolic odor
External identifiers / databases
CAS number 96-23-1 EC number 202-491-9 ECHA InfoCard 100.002.266 PubChem 7289 Wikidata Q10843705
properties
Molar mass	128.99 g mol −1
Physical state	liquid
density	1.39 g cm −3
Melting point	−4 ° C
boiling point	175 ° C
Vapor pressure	0.72 mbar (20 ° C)
solubility	Easily soluble in water (110 g l −1 at 20 ° C)
Refractive index	1.4835 (20 ° C, 589 nm)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 301-312-350 P: 201-280-301 + 310-308 + 313
Toxicological data	110 mg kg −1 ( LD 50 ,  rat ,  oral ) 1080 mg kg −1 ( LD 50 ,  rabbit ,  transdermal )
Thermodynamic properties
ΔH f 0	−385.3 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

1,3-dichloro-2-propanol (1,3-DCP) is a chemical compound from the group of alcohols and chlorine compounds and an important intermediate stage in the synthesis of the high production volume chemical epichlorohydrin . Because of its industrial importance, the compound has been intensively studied toxicologically.

Occurrence

1,3-DCP is formed when chloride ions act on lipid components of foods under different conditions, such as during preparation, cooking and storage.

The acid hydrolysis process that many manufacturers of soy sauces use, in addition to the formation of 3-chloro-1,2-propanediol (3-MCPD), always leads to 1,3-dichloro-2-propanol. The Federal Institute for Risk Assessment (BfR) has set a limit value in food for 3-MCPD, but not for 1,3-DCP. According to some scientists, 1,3-DCP can cause cancer. This can be passed on in affected sex cells to subsequent generations who have never been exposed to the chemical.

In addition to soy sauces, 1,3-DCP has also been found in acid-treated vegetable protein preparations and in a variety of fish and meat products.

Extraction and presentation

In an early publication, glycerol is converted with disulfur dichloride in 62% yield to 1,3-dichloro-2-propanol.

The process is only of historical interest because of the unpleasant properties of S ₂ Cl ₂ .

A patent from 1912 is suitable for practical implementation.

For a large-scale industrial process, however, only continuous process management is suitable. Here, the hydrochlorination of glycerol is carried out instead of acetic acid with adipic acid as a catalyst at 130 ° C and with practically complete conversion of glycerol and HCl gas in a total yield of 93%, predominantly 1,3-dichloro-2-propanol and approx. 3% 2 , 3-dichloropropan-1-ol obtained.

The reaction ( esterification ) of glycerol with hydrogen chloride in the presence of an organic acid as a catalyst comprises several equilibrium reactions , such as. B. monochlorination, dichlorination, ether formation to diglycerin , chlorination of diglycerin, ester formation with the acid catalyst, etc., which cause yield losses of 1,3-DCP in non-optimized processes.

properties

1,3-dichloro-2-propanol is a colorless, hardly flammable liquid with a phenol- like odor that is easily soluble in water. It decomposes when heated, which can produce hydrogen chloride and phosgene .

use

Due to its toxicological properties, 1,3-DCP is no longer used as a solvent or for textile finishing.

The 1,3-dichloropropene used in the USA as a nematicide for soil treatment ( English soil fumigant ) can be obtained from 1,3-dichloro-2-propanol by splitting off water.

The mutagenic 1,2,3-trichloropropane is also formed when the secondary hydroxyl group in 1,3-dichloro-2-propanol is replaced by HCl.

With the rapid increase in inexpensive quantities of glycerol from biodiesel production in the 1990s, 1,3-dichloro-2-propanol became interesting again as an intermediate to "bio-epichlorohydrin" ( glycerol-to-epichlorohydrin GTE).

The optimized procedures, such as u. a. described in and z. As commercialized as Epicerol® technology (Solvay) or GTE process (DOW), lower by 60% were in multiple large-scale plants (> 100,000 tpa capacity) implemented in Asia and are CO2 balance (Engl. Carbon footprint ) than the petrochemical Have process via allyl chloride .

safety instructions

With acute poisoning, severe irritation of the mucous membranes, especially the eyes, occurs. Gastrointestinal disorders, liver damage and kidney dysfunction are also possible. The substance should be considered carcinogenic to humans. In a drinking water study on rats over 102 weeks, there was an increased incidence of malignant neoplasms in various locations (liver, kidneys, tongue, oral cavity, thyroid gland) in the highest dose groups (up to 30 mg / kg body weight) and slightly or not increased in the other two dose groups ).

Individual evidence

1. ↑ ^{a b c d e f g h i j k l m} Entry on 1,3-dichloro-2-propanol in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
2. ↑ Data sheet 1,3-dichloro-2-propanol (PDF) from Merck , accessed on April 24, 2012.
3. ↑ Entry on 1,3-dichloropropan-2-ol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-24.
5. ↑ National Toxicology Program (NTP): 1,3-dichloro-2-propanol, [CAS No. 96-23-1]. Review of Toxicological Literature. January 2005.
6. ↑ ^{a b} G. Williams, J.-C. Leblanc, RW Setzer: Application of the margin of exposure (MoE) approach to substances in food that are genotoxic and carcinogenic Example: (CAS No. 96-23-1) 1,3-dichloro-2-propanol (DCP) . In: Food Chem. Toxicol. tape 48 , 2010, p. S57 – S62 , doi : 10.1016 / j.fct.2009.10.038 .
7. ↑ Junelyn S. de la Rosa: Is your soy sauce safe? In: Bureau of Agricultural Research Chronicle. Volume 5, No. 5, May 2004, pp. 1-31 ( gov.ph ).
8. ↑ A. Claus: IV. About the representation of dichlorohydrin . In: Justus Liebigs Ann. Chem. Band 168 , no. 1 , 1873, p. 44-44 , doi : 10.1002 / jlac.18731680105 .
9. ↑ Patent DE197308 : Process for the preparation of mono- and dichlorohydrin from glycerine and gaseous hydrochloric acid. Registered November 20, 1906 , published April 16, 1908 , Applicant: CF Boehringer & Sons. ‌
10. ↑ ^{a b c} Patent EP1760060A1 : Process for preparing dichloropropanol from glycerol. Applied on November 18, 2004 , published on March 7, 2007 , Applicant: Solvay SA, Inventors: P. Krafft, P. Gilbeau, B. Gosselin, S. Claessens. ‌
11. ^ A. Almena, M. Martin: Technoeconomic analysis of the production of epichlorohydrin from glycerol . In: Ind. Eng. Chem. Res. Volume 55 , no. 12 , 2016, p. 3226-3238 , doi : 10.1021 / acs.iecr.5b02555 .
12. ^ M. Pagliano, M. Rossi: The future of glycerol: New usages for a versatile raw material . RSC Green Chemistry Series, Cambridge 2008, ISBN 978-1-84973-046-4 , pp. 47-53 .
13. ^ BM Bell et al .: Glycerin as a renewable feedstock for epichlorohydrin production. The GTE process . In: CLEAN - Soil, Air, Water . tape 36 , no. 8 , 2008, p. 657-661 , doi : 10.1002 / clen.200800067 .
14. ↑ Guy-Noël Sauvion: Process Innovation focused on Sustainable Chemistry ( Memento from April 16, 2016 in the Internet Archive ). ISGC, May 6th 2015, La Rochelle.