2-chloro-6,7-dimethoxyquinazolin-4-amine

Endpoint summary

Description of key information

Acute oral toxicity: 

LD50 was estimated to be 958 mg/kg bw when male and female Wistar rats were treated with 2-Chloro-6, 7-dimethoxyquinazolin-4-amine by oral gavage route.

Acute Dermal toxicity: 

LD50 was estimated to be 3652 mg/kg bw when New Zealand White male rabbits were treated with 2-Chloro-6, 7-dimethoxyquinazolin-4-amine by dermal application occlusively for 24 h.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

Data is predicted using OECD QSAR toolbox version 3.4 and the supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: estimated

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.4

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Specific details on test material used for the study:

- IUPAC Name: 2-Chloro-6,7-dimethoxyquinazolin-4-amine
- Mol. formula: C10H10ClN3O2
- Molecular Weight: 239.661 g/mole
- Smiles: n1c(c2cc(OC)c(cc2nc1Cl)OC)N
- InChI: 1S/C10H10ClN3O2/c1-15-7-3-5-6(4-8(7)16-2)13-10(11)14-9(5)12/h3-4H,1-2H3,(H2,12,13,14)

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

not specified

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

not specified

Doses:

958 mg/kg

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

not specified

Statistics:

not specified

Preliminary study:

not specified

Sex:

male/female

Dose descriptor:

LD50

Effect level:

958 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Mortality:

not specified

Clinical signs:

other: not specified

Gross pathology:

not specified

Other findings:

not specified

The prediction was based on dataset comprised from the following descriptors: LD50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

(((("a" or "b" or "c" or "d" )  and ("e" and ( not "f") )  )  and ("g" and ( not "h") )  )  and ("i" and "j" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Non-covalent interaction AND Non-covalent interaction >> DNA intercalation AND Non-covalent interaction >> DNA intercalation >> Fused-Ring Primary Aromatic Amines AND Radical AND Radical >> Radical mechanism via ROS formation (indirect) AND Radical >> Radical mechanism via ROS formation (indirect) >> Fused-Ring Primary Aromatic Amines AND SN1 AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Fused-Ring Primary Aromatic Amines by DNA binding by OASIS v.1.4

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) AND AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) >> Heterocyclic Aromatic Amines AND Radical reactions AND Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base AND Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines AND SE reaction (CYP450-activated heterocyclic amines) AND SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base  AND SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base  >> Heterocyclic Aromatic Amines AND SNAr AND SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds AND SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds >> Activated aryl and heteroaryl compounds AND SR reaction (peroxidase-activated heterocyclic amines) AND SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base AND SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines by Protein binding by OASIS v1.4

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SNAr AND SNAr >> Nucleophilic aromatic substitution AND SNAr >> Nucleophilic aromatic substitution >> Halo-pyrimidines by Protein binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Anilines (Unhindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Non-covalent interaction AND Non-covalent interaction >> DNA intercalation AND Non-covalent interaction >> DNA intercalation >> Fused-Ring Primary Aromatic Amines AND Radical AND Radical >> Radical mechanism via ROS formation (indirect) AND Radical >> Radical mechanism via ROS formation (indirect) >> Fused-Ring Primary Aromatic Amines AND SN1 AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Fused-Ring Primary Aromatic Amines by DNA binding by OASIS v.1.4

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as AN2 OR AN2 >> Schiff base formation OR AN2 >> Schiff base formation >> Polarized Haloalkene Derivatives OR AN2 >> Schiff base formation by aldehyde formed after metabolic activation OR AN2 >> Schiff base formation by aldehyde formed after metabolic activation >> Geminal Polyhaloalkane Derivatives OR AN2 >> Shiff base formation after aldehyde release OR AN2 >> Shiff base formation after aldehyde release >> Specific Acetate Esters OR AN2 >> Thioacylation via nucleophilic addition after cysteine-mediated thioketene formation OR AN2 >> Thioacylation via nucleophilic addition after cysteine-mediated thioketene formation >> Haloalkenes with Electron-Withdrawing Groups OR AN2 >> Thioacylation via nucleophilic addition after cysteine-mediated thioketene formation >> Polarized Haloalkene Derivatives OR No alert found OR Non-covalent interaction >> DNA intercalation >> DNA Intercalators with Carboxamide and Aminoalkylamine Side Chain OR Radical >> Radical mechanism via ROS formation (indirect) >> Diazenes and Azoxyalkanes OR Radical >> Radical mechanism via ROS formation (indirect) >> Geminal Polyhaloalkane Derivatives OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroaniline Derivatives OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroarenes with Other Active Groups OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitrophenols, Nitrophenyl Ethers and Nitrobenzoic Acids OR Radical >> Radical mechanism via ROS formation (indirect) >> p-Aminobiphenyl Analogs OR Radical >> Radical mechanism via ROS formation (indirect) >> Single-Ring Substituted Primary Aromatic Amines OR SN1 >> Carbenium ion formation OR SN1 >> Carbenium ion formation >> Alpha-Haloethers OR SN1 >> Direct nucleophilic attack on diazonium cation (DNA alkylation) OR SN1 >> Direct nucleophilic attack on diazonium cation (DNA alkylation) >> Diazenes and Azoxyalkanes OR SN1 >> Nucleophilic attack after carbenium ion formation OR SN1 >> Nucleophilic attack after carbenium ion formation >> Specific Acetate Esters OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation >> Nitroarenes with Other Active Groups OR SN1 >> Nucleophilic attack after nitrenium ion formation OR SN1 >> Nucleophilic attack after nitrenium ion formation >> p-Aminobiphenyl Analogs OR SN1 >> Nucleophilic attack after nitrenium ion formation >> Single-Ring Substituted Primary Aromatic Amines OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroaniline Derivatives OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroarenes with Other Active Groups OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitrophenols, Nitrophenyl Ethers and Nitrobenzoic Acids OR SN2 OR SN2 >> Acylation OR SN2 >> Acylation >> Specific Acetate Esters OR SN2 >> Acylation involving a leaving group after metabolic activation OR SN2 >> Acylation involving a leaving group after metabolic activation >> Geminal Polyhaloalkane Derivatives OR SN2 >> Alkylation OR SN2 >> Alkylation >> Alkylphosphates, Alkylthiophosphates and Alkylphosphonates OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation >> Haloalkenes with Electron-Withdrawing Groups OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation >> Polarized Haloalkene Derivatives OR SN2 >> Nucleophilic substitution at sp3 Carbon atom OR SN2 >> Nucleophilic substitution at sp3 Carbon atom >> Specific Acetate Esters OR SN2 >> Nucleophilic substitution at sp3 carbon atom after thiol (glutathione) conjugation OR SN2 >> Nucleophilic substitution at sp3 carbon atom after thiol (glutathione) conjugation >> Geminal Polyhaloalkane Derivatives OR SN2 >> SN2 at sp3 and activated sp2 carbon atom OR SN2 >> SN2 at sp3 and activated sp2 carbon atom >> Polarized Haloalkene Derivatives OR SN2 >> SN2 at sp3-carbon atom OR SN2 >> SN2 at sp3-carbon atom >> Alpha-Haloethers OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 >> Nitroarenes with Other Active Groups by DNA binding by OASIS v.1.4

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Not categorized by Repeated dose (HESS)

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Benzene/ Naphthalene sulfonic acids (Less susceptible) Rank C by Repeated dose (HESS)

Domain logical expression index: "i"

Parametric boundary:The target chemical should have a value of log Kow which is >= -0.124

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of log Kow which is <= 3.85

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

LD50 was estimated to be 958 mg/kg bw when male and female Wistar rats were treated with 2-Chloro-6,7-dimethoxyquinazolin-4-amine by oral gavage route.

Executive summary:

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for  2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680 -84 -4). The LD50 was estimated to be 958 mg/kg bw when male and female Wistar rats were treated with 2-Chloro-6,7-dimethoxyquinazolin-4-amine by oral gavage route.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

958 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from QSAR Toolbox 3.4

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

Data is predicted using OECD QSAR toolbox version 3.4 and the supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: estimated

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.4

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Specific details on test material used for the study:

- IUPAC Name: 2-Chloro-6,7-dimethoxyquinazolin-4-amine
- Mol. formula: C10H10ClN3O2
- Molecular Weight: 239.661 g/mole
- Smiles: n1c(c2cc(OC)c(cc2nc1Cl)OC)N
- InChI: 1S/C10H10ClN3O2/c1-15-7-3-5-6(4-8(7)16-2)13-10(11)14-9(5)12/h3-4H,1-2H3,(H2,12,13,14)

Species:

rabbit

Strain:

New Zealand White

Sex:

male

Details on test animals or test system and environmental conditions:

not specified

Type of coverage:

occlusive

Vehicle:

not specified

Details on dermal exposure:

not specified

Duration of exposure:

24 h

Doses:

3652 mg/kg

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

not specified

Statistics:

not specified

Preliminary study:

not specified

Sex:

male

Dose descriptor:

LD50

Effect level:

3 652 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Mortality:

not specified

Clinical signs:

other: not specified

Gross pathology:

not specified

Other findings:

not specified

The prediction was based on dataset comprised from the following descriptors: LD50
Estimation method: Takes average value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

((((("a" or "b" or "c" or "d" )  and ("e" and ( not "f") )  )  and "g" )  and "h" )  and ("i" and "j" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Non-covalent interaction AND Non-covalent interaction >> DNA intercalation AND Non-covalent interaction >> DNA intercalation >> Fused-Ring Primary Aromatic Amines AND Radical AND Radical >> Radical mechanism via ROS formation (indirect) AND Radical >> Radical mechanism via ROS formation (indirect) >> Fused-Ring Primary Aromatic Amines AND SN1 AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Fused-Ring Primary Aromatic Amines by DNA binding by OASIS v.1.4

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) AND AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) >> Heterocyclic Aromatic Amines AND Radical reactions AND Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base AND Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines AND SE reaction (CYP450-activated heterocyclic amines) AND SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base  AND SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base  >> Heterocyclic Aromatic Amines AND SNAr AND SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds AND SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds >> Activated aryl and heteroaryl compounds AND SR reaction (peroxidase-activated heterocyclic amines) AND SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base AND SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines by Protein binding by OASIS v1.4

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SNAr AND SNAr >> Nucleophilic aromatic substitution AND SNAr >> Nucleophilic aromatic substitution >> Halo-pyrimidines by Protein binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Anilines (Unhindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Not known precedent reproductive and developmental toxic potential by DART scheme v.1.0

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Known precedent reproductive and developmental toxic potential OR NO2-alkyl/NO2-benzene derivatives (8b) OR Non-steroid nucleus derived estrogen receptor (ER) and androgen receptor (AR) OR Non-steroid nucleus derived estrogen receptor (ER) and androgen receptor (AR) >> Other non-steroidal estrogen receptor (ER) binding compounds (2b-2) OR Toluene and small alkyl toluene derivatives (8a) by DART scheme v.1.0

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "h"

Similarity boundary:Target: COc1cc2c(cc1OC)c(N)nc(Cl)n2
Threshold=40%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "i"

Parametric boundary:The target chemical should have a value of log Kow which is >= 0.239

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.72

Interpretation of results:

Category 5 based on GHS criteria

Remarks:

Migrated information

Conclusions:

LD50 was estimated to be 3652 mg/kg bw when New Zealand White male rabbits were treated with 2-Chloro-6,7-dimethoxyquinazolin-4-amine by dermal application occlusively for 24 h.

Executive summary:

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for  2-Chloro-6,7-dimethoxyquinazolin-4-amine ( 23680-84-4). The LD50 was estimated to be 3652 mg/kg bw when New Zealand White male rabbits were treated with 2-Chloro-6,7-dimethoxyquinazolin-4-amine by dermal application occlusively for 24 h.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

3 652 mg/kg bw

Quality of whole database:

Data is Klimicsh 2 and from QSAR toolbox 3.4

Additional information

Acute oral toxicity:

In different studies, 2-chloro-6, 7-dimethoxyquinazolin-4-amine (CAS no 23680-84-4) has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments in rodents, i.e. most commonly in rats for 2-chloro-6, 7-dimethoxyquinazolin-4-amine along with the study available on structurally similar read across substance Triamterene (CAS no 396-01-0) and Pyrido(2,3-d)pyrimidine-2,4-diamine, 6-((2,5-dimethoxyphenyl)methyl)-5-methyl- (CAS no 72732-56-0). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680 -84 -4). The LD50 was estimated to be 958 mg/kg bw when male and female Wistar rats were treated with 2-Chloro-6,7-dimethoxyquinazolin-4-amine by oral gavage route.

The above study supported by U.S. Department of Health and Human Services (NTP Technical Report, 1993), for the structurally similar read across substanceTriamterene

(CAS no 396-01-0). Theacute oral toxicity study was conducted in rat at the concentration of 400 mg/kg bw by oral route. 50 % mortality observed in treated rats at 400 mg/kg bw. Therefore, LD50 was considered to be 400 mg/kg bw when rat were treated with Triamterene orally.

This is further supported by RTECS database (2017), for the structurally similar read across substancePyrido(2,3-d)pyrimidine-2,4-diamine, 6-((2,5-dimethoxyphenyl)methyl)-5-methyl- (CAS no 72732-56-0). The acute oral toxicity study was conducted in rats at the concentration of 1168 mg/kg bw by oral route. 50 % mortality observed in treated rats at 1168 mg/kg bw. Therefore, LD50 was considered to be 1168 mg/kg bw when rat were treated with Pyrido(2,3-d)pyrimidine-2,4-diamine, 6-((2,5-dimethoxyphenyl)methyl)-5-methyl- orally. 

 

Thus, based on the above studies on 2-chloro-6, 7-dimethoxyquinazolin-4-amine (CAS no 23680-84-4) and it’s read across substances, it can be concluded that LD50 value is between 300 - 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-chloro-6, 7-dimethoxyquinazolin-4-amine can be classified as category IV of acute oral toxicity.

Acute Dermal toxicity:

In different studies, 2-chloro-6, 7-dimethoxyquinazolin-4-amine (CAS no 23680-84-4) has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments in rodents, i.e. most commonly in rabbits and rats for 2-chloro-6, 7-dimethoxyquinazolin-4-amine along with the study available on structurally similar read across substance 4-Chloroaniline (106-47-8) and 4-chloro-2,5-dimethoxyaniline (6358-64-1). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for 2-Chloro-6,7-dimethoxyquinazolin-4-amine ( 23680-84-4). The LD50 was estimated to be 3652 mg/kg bw when New Zealand White male rabbits were treated with 2-Chloro-6, 7-dimethoxyquinazolin-4-amine by dermal application occlusively for 24 h.

This is further supported by U.S. National Library of Medicine, ChemIDplus (2017), for the structurally similar read across substance4-Chloroaniline (106-47-8). The acute dermal toxicity study was conducted in rats at the concentration of 3200 mg/kg bw. 50% mortality was observed at 3200 mg/kg bw. Therefore, LD50 was consider to be 3200 mg/kg bw, when rat was treated with 4-Chloroaniline by dermal application.

The above study supported by GESTIS SUBSTANCE Database (2017), for the structurally similar read across substance 4-chloro-2,5-dimethoxyaniline (6358-64-1).The acute dermal toxicity study was conducted according to OECD 402 in rats at the concentration of 2000 mg/kg bw. No mortality was observed at 2000 mg/kg bw. The animals did not reveal any signs of toxicity. In Gross pathology examination there was no visible organ damage among the animals macroscopically. Therefore, LD50 was consider to be >2000 mg/kg bw, when rat was treated with 4-chloro-2, 5-dimethoxyaniline by dermal application.

Thus, based on the above studies on 2-chloro-6, 7-dimethoxyquinazolin-4-amine (CAS no 23680-84-4) and it’s read across substances, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-chloro-6, 7-dimethoxyquinazolin-4-amine can be classified as category V of acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies and prediction on 2-chloro-6, 7-dimethoxyquinazolin-4-amine (CAS no 23680-84-4) and it’s read across substances, it can be concluded that the LD50 value isbetween 300 - 2000 mg/kg bw for acute oral toxicity and greater than 2000 mg/kg bw for acute dermal toxicity. Thus, comparing these values with the criteria of CLP regulation, 2-chloro-6, 7-dimethoxyquinazolin-4-amine can be classified as category IV for acute oral toxicity and category V for acute dermal toxicity.