Methyl 3-aminopyrazinecarboxylate

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 February 2013 - 26 April 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

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:

Methyl 3-aminopyrazinecarboxylate

EC Number:

240-387-5

EC Name:

Methyl 3-aminopyrazinecarboxylate

Cas Number:

16298-03-6

Molecular formula:

C6H7N3O2

IUPAC Name:

methyl 3-aminopyrazine-2-carboxylate

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Amiloride Compound 6
- Description: Tan powder
- Storage condition of test material: In refrigerator (2-8°C) protected from light, desiccated
- Other: Reactive to light, moisture and oxygen

Results and discussion

Melting / freezing point

Melting / freezing pt.:

170 °C

Decomposition:

yes

Remarks on result:

other: Melt. pt.: 443 K; Decomposition during melting.

Any other information on results incl. tables

PRELIMINARY TEST WITH TGA

From 200°C upwards the weight of the sample decreased significantly. At 254°C, the sample weight had decreased by 25%. After the experiment, a brown/black molten residue remained in the sample container.

 

DSC EXPERIMENTS

Experiment 1: Endothermic peak between 150°C and 200°C (extrapolated onset temperature: 169.84°C). Based on observations and the observed weight loss from approximately 150°C in the TGA test, the effect was most likely obtained due to melting and reaction and/or decomposition of the test substance. From 225°C an endothermic effect started (reaction and/or decomposition of the test substance). After the experiment, a brown/black molten residue remained in the sample container.

 

Experiment 2: To investigate the endothermic peak between 150°C and 200°C a lower heating rate of 5°C/minute was applied. Extrapolated onset temperature of the endothermic peak: 169.22°C (not used for the result due to the low heating rate). The similar value obtained demonstrated that melting of the test substance was the reason for the endothermic effect. It is possible that reaction and or decomposition was also the reason for the effect. From 200°C an endothermic effect followed by an exothermic effect were observed. This effect was due to reaction and/or decomposition of the test substance. After the experiment, a black molten residue remained in the sample container.

 

Experiment 3: A lower end temperature was applied for visual observation of the residue after the endothermic effect. Extrapolated onset temperature: 169.95°C.After the experiment, a dark brown molten residue remained in the sample container. It indicated that reaction and/or decomposition of the test substance had occurred during melting.

 

TGA/DSC curves: see attached document. The melting temperature of the test substance was calculated from the results obtained in Experiment 1 and Experiment 3.

Applicant's summary and conclusion

Conclusions:

The melting temperature of Amiloride Compound 6 was determined to be 170°C using differential scanning calorimetry (GLP-compliant study in accordance with EC A.1, OECD 102 and EPA OPPTS 830.7200). The substance decomposes during melting.