Pentanedioic acid, 2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-, (2S)-

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 June 2015-18 August 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP-compliant study in accordance with EC A.1 and OECD 102.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

(2008)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

(1995)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Version / remarks:

(1998)

Deviations:

no

GLP compliance:

yes

Type of method:

thermal analysis

Remarks:

(differential scanning calorimetry)

Test material

Test material information

Constituent 1

Reference substance name:

(2S)-2-(1,3-DIOXO-2,3-DIHYDRO-1H-ISOINDOL-2-YL)PENTANEDIOIC ACID

EC Number:

608-945-6

Cas Number:

340-90-9

Molecular formula:

C13H11NO6

IUPAC Name:

(2S)-2-(1,3-DIOXO-2,3-DIHYDRO-1H-ISOINDOL-2-YL)PENTANEDIOIC ACID

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name (as cited in study report): Phthalyl-L-Glu
- Appearance: white powder
- Storage conditions: room temperature

Results and discussion

Melting / freezing point

Key result

Melting / freezing pt.:

161 °C

Decomposition:

yes

Decomp. temp.:

200 °C

Remarks on result:

other: Melt. pt: 434 K. Decomp. temp: 473 K.

Any other information on results incl. tables

TGA EXPERIMENT

From 300°C upwards the weight of the sample decreased significantly. At 359°C, the sample weight had decreased by 25%. After the experiment, a black molten residue remained in the sample container.  

 

DSC EXPERIMENT 1

An endothermic peak between 125°C and 200°C was observed. The endothermic peak had two maxima; with extrapolated onset temperatures of 156.67°C and 160.73°C. The effect was most likely obtained due to melting of the test substance. Two endothermic peaks were observed from 200°C. The effect was most likely obtained due to reaction and/or decomposition of the test substance. After the experiment, a dark brown molten residue remained in the sample container.  

 

DSC EXPERIMENT 2

To investigate reaction and/or decomposition, a lower heating rate of 5°C/minute was applied. The extrapolated onset temperatures were 155.63°C and 160.38°C. The similar result obtained demonstrated that melting of the test substance was the reason for the endothermic effect. Since a lower heating rate was applied, the extrapolated onset temperatures were not used for calculation of the melting temperature. After the experiment, a dark brown molten residue remained in the sample container.

 

DSC EXPERIMENT 3

To investigate the melting peak, a repeated heating cycle was applied. With the first heating the extrapolated onset temperatures were 156.69°C and 160.30°C.  During cooling a glass transition was observed between 0°C and 50°C.  With the second heating, a glass transition was observed between 25°C and 75°C. The inflection point of the glass temperature was 49.43°C. The results demonstrated that the endothermic effect was due to melting of the test substance. After the experiment, a dark brown molten residue remained in the sample container.

Applicant's summary and conclusion

Conclusions:

In a GLP-compliant study in accordance with EC A.1, OECD 102 and EPA OPPTS 830.7200 using differential scanning calorimetry, the melting temperature of the substance has been determined as 161°C. Decomposition started at 200°C.