2-amino-2-ethylpropanediol

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

before 12 Apr 2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

simple distillation and alternate method (reducing the heat history and blanketing the substance with nitrogen)

GLP compliance:

no

Type of method:

distillation method

Boiling pt.:

>= 259 - <= 260 °C

Atm. press.:

ca. 1 013 hPa

Decomposition:

yes

The determination of the AEPD's boiling point by simple distillation:

Fraction No.	Temp. range, °C	Weight obtained, g	Comment	GC Analysis (% AEPD)
1	RT-250	0.5	2 phases	8.5
2	250-259	1.0	yellow oil	80
3	259-260	2.0	yellow oil	94
4	>260	0.5	yellow oil	98.9

The majority of the substance distilled overhead in Fraction 3 (259-260 °C) even though some decomposition occurred at these elevated temperatures while open to the atmosphere. The purity dropped to 94.4 area% in the main fraction collected. Thus it appeared possible that this measured bp was lower than the actual value.

The results of the boiling point determination of AEPD at atmospheric pressure:

Measure No.	Method used	Boiling point, °C	Device used	AEPD purity, area%
1	Distillation (method 1)	259-260	Thermometer #1	94.4
2	Boiling point (method 2)	259.0	Thermometer #2	99.8
3	Boiling point (method 2)	260.0	Thermometer #3	~99
4	Boiling point (method 2)	253.5	Thermometer #4	~97
5	Boiling point (method 2)	262.2	J Thermocouple	~96
6	Boiling point (method 2)	256.5	Thermometer #5	~95
7	Boiling point (method 2)	258.0	Thermometer #3	93.2

Heating the substance to its boiling point at atmospheric pressure had caused decomposition to occur. While this was most apparent when performing the simple distillation using a short path distillation system to take the AEPD overhead, the alternate method also resulted in decomposition even thought it was run under nitrogen and had a shorter heat history. Obviously this decomposition affects the reported bp as measurement #3 and #7 used the same thermometer / set-up; yet the bp for measurement #3 (99.5 area%) was 2.0 °C more than measurement #7 (93.2 area%) that had been heated for about an hour under nitrogen. Therefore adding 2.0 °C to run #7 and then throwing the low and the high bp values out, a value of 259 °C is reached as the boiling point of the AEPD. This matches the simple distillation value previously obtained.

Conclusions:

The AEPD (2-amino-2-ethyl-1,3-propanediol) standard was prepared and then characterized by GC, GC/MS (EI and CI), NMR (1H and 13C), IR and titration determination that confirmed the assigned structure. This high purity material (99.5+%) was subsequently used to determine its boiling point as 259-260 °C at atmospheric pressure by two different methods.

Description of key information

259-260 °C at ambient pressure

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

259 °C

Additional information

Distillation method. Decomposition occurs. Under reduced pressure of 10 mmHg, 152 -153 °C reported (handbook data).