Dimethyl propylene urea

Structural formula
General
Surname	Dimethyl propylene urea
other names	DMPU N , N -dimethyl N , N -trimethylenharnstoff 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1 H ) -pyrimidinone
Molecular formula	C 6 H 12 N 2 O
Brief description	hygroscopic colorless liquid with a characteristic odor
External identifiers / databases
CAS number 7226-23-5 EC number 230-625-6 ECHA InfoCard 100,027,841 PubChem 81646 Wikidata Q416637
properties
Molar mass	128.17 g mol −1
Physical state	liquid
density	1.064 g cm −3 (20 ° C) 1.0593 g cm −3 (25 ° C)
Melting point	−24 ° C
boiling point	247 ° C
Vapor pressure	0.5 hPa (57 ° C)
solubility	soluble in water
Refractive index	1.489 (20 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 302-318-361f P: 280-305 + 351 + 338-313
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

Dimethylpropyleneurea (or DMPU ) is a cyclic urea .

properties

Dimethylpropyleneurea is a hygroscopic colorless liquid with a characteristic odor, which is soluble in water. Your aqueous solution has an alkaline reaction. The boiling point at normal pressure is 247 ° C. According to Antoine, the vapor pressure function results from ln (P) = A− (B / (T + C)) (P in bar, T in K) with A = 9.26224, B = 3867.206 and C = −102.346 im Temperature range from 368 to 511 K. The enthalpy of vaporization at the boiling point is 48.10 kJ · mol ⁻¹ .

The density of DMPU decreases with increasing temperature. The function of the temperature dependency can be described with a quadratic equation according to ρ = α + β · T + γ · T ² with α = 1.31475, β = −8.7668 · 10 ⁻⁴ and γ = 0.66723 · 10 ⁻⁷ .

Density of DMPU
temperature	in ° C	25th	40	60	80	100
density	in g cm −3	1.0593	1.0467	1.0301	1.0135	0.9969

Dimethylpropyleneurea forms vapor-air mixtures that are difficult to ignite. The compound has a flash point of 121 ° C. The explosion range is between 1.6 vol.% As the lower explosion limit (LEL) and 9.3 vol.% As the upper explosion limit (UEL). The ignition temperature is 255 ° C. The substance therefore falls into temperature class T3.

use

Dimethylpropyleneurea is used in organic synthesis as a polar aprotic solvent or cosolvent. First and foremost, the carcinogenic hexamethylphosphoric acid triamide (HMPT) is being replaced by the toxicologically less harmful DMPU. Like HMPT, DMPU is able to break up lithium clusters in carbanion chemistry and solvate lithium cations. This significantly increases the reactivity of the carbanions. In addition, DMPU is used as a solvent in the electronics industry.

Individual evidence

1. ↑ ^{a b c d e f g h i j k l} Entry on dimethylpropyleneurea in the GESTIS substance database of the IFA , accessed on February 2, 2018(JavaScript required) .
2. ↑ ^{a b c d e f} Kneisl, P .; Zondlo, JW: Vapor pressure, liquid density, and the latent heat of vaporization as functions of temperature for four dipolar aprotic solvents in J. Chem. Eng. Data 32 (1987) 11-13, doi : 10.1021 / je00047a003
3. ↑ Data sheet 1,3-Dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone from Sigma-Aldrich , accessed on April 10, 2011 ( PDF ).
4. ↑ Entry on Tetrahydro-1,3-dimethyl-1H-pyrimidin-2-one in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ Triptikumar Mukhopadhyay, Dieter Seebach : substitution of HMPT by the cyclic urea DMPU as a cosolvent for highly reactive nucleophilic and bases , in: Helvetica Chimica Acta , 1982 , 65 , pp 385-391; doi : 10.1002 / hlca.19820650141 .
6. ↑ Entry on propylene urea. In: Römpp Online . Georg Thieme Verlag, accessed on February 2, 2018.
7. ^ C. Elschenbroich, A. Salzer: Organometallics - A Concise Introduction. 2nd Ed., Wiley-VCH, Weinheim 1995, ISBN 3-527-28164-9 .
8. ↑ DMPU on the homepage of BASF AG