3-acetoxymethylen-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 27, 2012 - September 18, 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study (OECD102) with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

GLP compliance:

no

Type of method:

thermal analysis

Test material

Test material information

Constituent 1

Reference substance name:

3-acetoxymethylen-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

EC Number:

213-485-0

EC Name:

3-acetoxymethylen-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Cas Number:

957-68-6

Molecular formula:

C10H12N2O5S

IUPAC Name:

(6R,7R)-3-[(acetyloxy)methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): 7-Aminocephalosporanic acid
- Lot/batch No.: B146988

Results and discussion

Melting / freezing point

Decomposition:

yes

Decomp. temp.:

>= 180 °C

Any other information on results incl. tables

In all three measurements a broad exothermal effect could be observed in a temperature range of 190 – 360 °C with a decomposition energy of -190 J/g (mean value). In all three measurements amass loss of approximately 68 % could be observed.

Table: Results on melting and boiling point

No.	Sample weight / mg	Start of effect / °C	Energy / J/g	Remark
PN4233	13.94	200	-190 (exothermal)
PN4242	10.58	210	-170 (exothermal)
PN4262	12.04	190	-210(exothermal)

Applicant's summary and conclusion

Conclusions:

According to OECD Test Guidelines 102 and 103, and EC No. 440/2008 Part A. Method A.1. and A.2., the test item 7-Aminocephalosporanic acid has no melting and no boiling point at atmospheric pressure (1013 hPa). It decomposes firstly at a temperature of 180 °C.

Executive summary:

In this test, the thermal stability and the melting and boiling temperatures of the test item were investigated by DSC (differential scanning calorimetry). With this method the difference in energy input into the test item and a reference material as a function of temperature was recorded, while the substance and reference material were subjected to the same temperature program. This energy was the energy necessary to establish zero temperature difference between the substance and the reference material. When the sample underwent a transition involving a change of enthalpy, that change was indicated by an endothermic departure (e.g. melting, boiling) from the base line of the heat flow record. As result, a thermogram was created in which the transition heat flow was exhibited as a function of the temperature. In this diagram, the onset of the process (e.g. decomposition, physical process) as well as the heat flow of the process was shown.

For the first two tests the test item was weighed in under air into aluminium crucibles. About 11 ‑ 14 mg of the test item were weighed in for the tests. The crucible was closed with a cover. In the cover was a small hole. As reference crucibles, empty aluminium crucibles were used.

For one further test the test item was weighed in under air into a glass crucible. About 12 mg of the test item were weighed in for the test. The upper end of the crucible was closed by melting with an oxyhydrogen flame and opened afterwards by breaking off the top. As reference crucibles, glass crucibles with aluminium oxide were used.