2-isocyanatoethyl methacrylate

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

23 - 24 Nov 2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study with acceptable restrictions: The preliminary test was performed over a test period of 10 minutes. No main test is performed although recommended for unstable substances. The determination and documentation of the hydrolysis products are not sufficient.

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

yes

Remarks:

no main test is conducted although recommended for unstable substances; the hydrolysis products are not adequately identified

GLP compliance:

no

Remarks:

no further information

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: after 10 minutes
- Sampling method: One pair of samples was processed for analysis immediately, whilst another pair was returned to the water bath for 10 min. prior to processing.

Buffers:

- pH: 4
- Composition of buffer: Potassium dihydrogen orthophosphate (3.00 g) and disodium hydrogen orthophosphate dodecahydrate (6.40 g) were dissolved in purified water (950 ml) and the pH was adjusted to 4.0 ± 0.05 with orthophosphoric acid. The volume was then adjusted to 1000 ml with purified water.
- pH: 7
- Composition of buffer: Potassium dihydrogen orthophosphate (6.80 g) was dissolved in purified water (950 ml), 1M sodium hydroxide (30 ml) was added and the pH was adjusted to 7.0 ± 0.05 with 1M hydrochloric acid. The volume was then adjusted to 1000 ml with purified water.
- pH: 9
- Composition of buffer: Disodium tetraborate decahydrate (16.6 g) and potassium dihydrogen orthophosphate (1.80 g) were dissolved in purified water (950 ml) and the pH was adjusted to 9.0 ± 0.05 with 1M hydrochloric acid.. The volume was then adjusted to 1000 ml with purified water.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: not specified

TEST MEDIUM
- Volume used/treatment: 10 mL
- Kind and purity of water: purified water (not specified)
- Preparation of test medium: Aliquots (100 μlL) of a stock solution of the test material in acetonitrile (10 g/L) were added to vials containing buffer solution (10 mL), which had been purged with nitrogen and pre-equilibrated at test temperature (50 °C) in a water bath. This produced test solutions of nominal concentration 100 mg/L.
- Identity and concentration of co-solvent: acetonitrile (10 g/L)

Duration:

10 min

Temp.:

50 °C

Initial conc. measured:

100 mg/L

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Transformation products:

yes

No.:

#1

Details on hydrolysis and appearance of transformation product(s):

The preliminary OECD 111 study shows that the substance is instable in water. Thus, according to the guideline no main test has to be performed.

% Recovery:

4.29 - 4.66

pH:

4

Temp.:

50 °C

Duration:

10 min

% Recovery:

19.28 - 29.3

pH:

7

Temp.:

50 °C

Duration:

10 min

% Recovery:

39.36 - 42.85

pH:

9

Temp.:

50 °C

Duration:

10 min

pH:

4

Temp.:

50 °C

DT50:

< 10 min

Type:

(pseudo-)first order (= half-life)

pH:

7

Temp.:

50 °C

DT50:

< 10 min

Type:

(pseudo-)first order (= half-life)

pH:

9

Temp.:

50 °C

DT50:

< 10 min

Type:

(pseudo-)first order (= half-life)

Details on results:

The preliminary study showed that at pH 4, 7 and 9 and 50 °C, greater than 50% hydrolysis had occured after 10 minutes, indicating a half-life of significantly less than 1 day under environmental conditions (25 °C).

Table 1: Preliminary investigation results for hydrolysis of the test substance

pH	Concentration [mg/L]
	T = 0 min		T = 10 min
	measured	mean	measured	mean
4	75.1, 74.5	74.8	3.5, 3.2	3.3
7	15.0, 22.3	18.7	4.4, 4.3	4.3
9	9.4, 8.4	8.9	3.7, 3.6	3.6

Reference 2

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented study report which meets basic scientific principles.

Qualifier:

no guideline available

Principles of method if other than guideline:

Determination of hydrolysis products of the test substance in water. The goal is to confirm the identity of a hydrolysis product of the test substance which was observed in the preliminary hydrolysis experiment (Shibuya, 2011).

GLP compliance:

no

Remarks:

no further information

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: The test substance and the metabolites were analyzed in the water and the test substance phase after 10 minutes. Additionally, a small portion of the test substance - water mix was analyzed after 3 days.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: not specified

OTHER TEST CONDITIONS
- Adjustment of pH: The pH was not controlled as according to to the preliminary hydrolysis study (Shibuya, 2011) pH showed to have no significant impact on the hydrolysis.

Number of replicates:

1

Positive controls:

no

Negative controls:

no

Preliminary study:

The goal of the study was to confirm the identity of a hydrolysis product of MOI which was observed in a preliminary hydrolysis experiment, study number MOI-20111125.

Test performance:

Test substance was mixed with deionized water (1:1; v:v). The mixture was vortexed for 10 min at room temperature. After phase separation the aqueous layer and the test substance layer were separated and the aqueous phase was extracted with CHCl3. The test substance / water ratio (1:1; v:v) was used to optimize the amount of hydrolysis product formed during the hydrolysis reaction. The chloroform layer was subsequently analyzed by GC-MS. In addition the aqueous layer and the organic test substance layer were analyzed by GC-MS and compared with GC-MS data obtained by GC-MS analysis of the test substance reference material provided by the sponsor. A small portion of the test substance / water mixture was further reacted over three days forming colourless crystals which were dissolved in acetonitrile and analysed by GC-MS.

Transformation products:

yes

No.:

#1

No.:

#2

Remarks on result:

other: The goal of the study was to confirm the identity of a hydrolysis product of MOI which was observed in a preliminary hydrolysis experiment, study number MOI-20111125.

Details on results:

After hydrolysis reaction the organic MOI layer (see attached scheme) showed beside the main component (MOI = parent compound; retention time 7 min.) one additional peak at a retention time of 17.4 min. This hydrolysis product (P1) was also detected in the aqueous layer of the hydrolysis reaction. The aqueous layer of the reaction was extracted with chloroform in accordance with the original hydrolysis experiment (Shibuya, 2011). The chloroform phase showed the same hydrolysis product with a retention time of 17.4 min, which was detected in the aqueous phase. The hydrolysis product P1 showed a signal at m/z 285 for M+H+ corresponding to a molecular weight of 284 g/mol, using chemical ionization (Cl) mass spectra. The observed molecular weight is in agreement with the structure of the hydrolysis product stated in the preliminary hydrolysis test ( N,N'-[2-(2-Methyl-2-propenoic acid) ethyl ester] urea; Shibuya, 2011).
An additional (smaller) peak was observed indicating a second hydrolysis product (P2) with an retention time between 5 and 6 min. The molecular weight was determined by Cl ionisation. The molecular weight of 129 g/mol is in agreement with the molecular weight of an amine formed by hydrolysis of the test substance (2 -aminoethyl methacrylate). The presence of this amine indicates that N,N'-[2-(2-Methyl-2- propenoic acid) ethyl ester] urea could be formed by a reaction of the parent compound with the amine.
Colourless crystals formed over three days during the reaction of the test substance with water were screened using GC and confirmed to be N,N'-[2-(2-Methyl-2- propenoic acid) ethyl ester] urea.

Description of key information

The estimated half-life at 50 °C was < 10 minutes, respectively.

Additional information

A study on the hydrolysis of 2 -isocyanatoethyl methacrylate was conducted by Shibuya (2011) according to OECD-guideline 111 in accordance with GLP requirements. In the test the hydrolysis of the test substance was investigated under different conditions. The resulting dissipation half-lives of the parent compound were below 10 minutes at pH 4, 7 and 9.

In a further supporting study, conducted by Weber (2012) the hydrolysis products of 2 -isocyanatoethyl methacrylate were identified as 2-aminoethyl methacrylate (CAS 7659 -36 -1) and N,N'-[2-(2-Methyl-2-propenoic acid) ethyl ester] urea (CAS 86219 -64 -9).