2-[7-(diethylamino)-2-oxo-2H-1-benzopyran-3-yl]quinazolin-4(1H)-one

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

October 05, 2017 - October 06, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: by loss of weight or by trapping vaporisate

Test material

Test material information

Constituent 1

Reference substance name:

3-(5-chlorobenzoxazol-2-yl)-7-(diethylamino)-2-benzopyrone

EC Number:

252-722-2

EC Name:

3-(5-chlorobenzoxazol-2-yl)-7-(diethylamino)-2-benzopyrone

Cas Number:

35773-43-4

Molecular formula:

C20H17ClN2O3

IUPAC Name:

3-(5-chloro-1,3-benzoxazol-2-yl)-7-(diethylamino)-2H-chromen-2-one

Test material form:

solid

Results and discussion

Vapour pressure

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

< 0 Pa

Any other information on results incl. tables

The vapour pressure was measured in the temperature range of 80 °C to 120 °C. The measured vapour pressures at the corresponding temperatures are listed in Table 1.After the measurement a mass loss of < 1 % (w/w) was determined.

Table1: Measured vapour pressures and corresponding temperatures

Temperature / °C	Vapour pressure / hPa
80	1.8 × 10^-6
90	4.2 × 10^-6
100	5.3 × 10^-6
110	3.4 × 10^-6
120	2.1 × 10^-6

 

Only for better readability the temperature is also reported in a centigrade scale. Since the test did not yield vapour pressures sufficiently high to extrapolate to 20, 25 and 50 °C these values were estimated. According to the Antoine equation, the vapour pressure can be calculated.

For an extrapolation to lower temperatures a conservative assumption of the Antoine constant C is 273.15. This results in a linear dependency of log(p) of the inverse Temperature 1/T (in K). Values for the resulting slope of the Antoine equation (constant B) for substances of high molecular weight, which can be derived from literature values (e.g. Handbook of Chemistry and Physics) are lower than -5000. Thus, for a conservative estimation of the vapour pressure of the test item at 20, 25 and 50 °C, a value of -5000 for constant B and a value of 273.15 for constant C, respectively, were used. The detection limit (1 × 10^-5hPa) at the highest measurement point (120 °C) was used for the calculation as all measured vapour pressures were below the detection limit. Based on this assumption, the constantAof the Antoine equation was calculated. Subsequently, the vapour pressure at 20, 25 and 50 °C can be calculated with the Antoine equation.

Table2: Calculated vapour pressure at 20, 25 and 50 °C

T / °C	p / hPa	p / Pa
20	< 4.6×10^-10	< 4.6×10^-8
25	< 8.9×10^-10	< 8.9×10^-8
50	< 1.8× 10^-8	< 1.8× 10^-6

This is a conservative estimation of the vapour pressure of the test item for the listed temperatures.

Applicant's summary and conclusion

Executive summary:

Based on the dectection limit (1 × 10^-5hPa) at the highest measurement point (120 °C) the following upper limit vapour pressure values for the test item were calculated:

T / °C	p / hPa	p / Pa
20	< 4.6×10^-10	< 4.6×10^-8
25	< 8.9×10^-10	< 8.9×10^-8
50	< 1.8× 10^-8	< 1.8× 10^-6