[1R-(1α,2β,5α)]-2-isopropyl-5-methylcyclohexyl 5-oxo-L-prolinate

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 October 2017 - 15 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling point/boiling range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Version / remarks:

2008

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP certificate (inspected on 15 to 16 November 2017 / signed on 15 May 2018)

Type of method:

method according to Siwoloboff

Decomposition:

yes

Decomp. temp.:

>= 166.5 °C

Remarks on result:

not determinable

Remarks:

potential pre-stage of decomposition suspected at 146°C

Results of pre-test following Siwoloboff method :

 

Table 4.3.1 Observations Pre-test for the boiling point following Siwoloboff

Observations	Temperatures
Fine condensate above the liquid visible	160 °C
Small bubbles visible	195 °C
Colour red-brown, lots of bubbles	205 °C
Burner switched off	220 °C
No bubbles visible anymore	195 °C

 

After cooling down, the test item appeared as a dark red-brown sticky mass.

 

Then, a main test was performed following Siwoloboff method.

Table 4.3.2 Observations Main-test for the boiling point following Siwoloboff

Observations	Temperatures
	First determination		Second determination
Now and then bubbles	144 °C
Colourless condensate visible	146.4 °C	146 °C
Yellow shine became more intense	166.9 °C	166.5 °C
Orange shine	174.8 °C	175 °C
Test item was red	182.3 °C	182 °C
Test item was red like blood	208 °C
Determination stopped, test item was dark red brown	228.1 °C	234.1 °C

After cooling down the item appeared as a black mass with red shine.

Decomposition was considered.

No boiling point could be determined because of decomposition of the test item.

The beginning decomposition indicated by the increasing of the yellow colour was clearly visible from 166.9 °C (first determination) and 166.5°C (second determination). The colourless condensate visible at 146.4 °C (first determination) and 146°C (second determination) might be a pre-stage of the decomposition.

Conclusions:

No boiling point could be determined because of decomposition of the test item from 166.5°C (colour change).
Potential pre-stage of decomposition was suspected at 146°C.

Executive summary:

A study was conducted to determine the boiling point of the test substance under GLP according to OECD 103 / EU A2 guideline.

The Siwoloboff method was performed to determine the initial boiling point of the substance.

However, a clear decomposition of the test item was observed from 166.5°C (colour change) and a potential pre-stage of decomposition was suspected at 146°C (colourless condensate observed).

Finally, no temperature of initial boiling point of the test item can be determined using SIwoloboff method, considering that the substance decomposed before boiling.

Description of key information

No boiling point could be determined because of decomposition of the test item from 166.5°C (colour change).

Potential pre-stage of decomposition was suspected at 146°C.

Additional information

A fully reliable GLP experimental study, conducted according to a recognized OECD/EC guidelines is available.

It is considered as a key study.