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Direct dyes

Direct Red 20

Also known as Fenamin pink B, Phenamine pink BT, Erie pink 2B

CAS 5850-73-7Formula C24H14ClN3Na2O7S3Molar mass 634.02 g/molEC 611-678-8
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Direct Red 20 chemical structure, C24H14ClN3Na2O7S3, CAS 5850-73-7
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
5850-73-7
Formula
C24H14ClN3Na2O7S3
Molar mass
634.02 g/mol
EC number
611-678-8
HS code
320414
Category
Direct dyes

What is Direct Red 20?

Plain description, key identifiers and synonyms

Direct Red 20 is a chemical substance with the molecular formula C24H14ClN3Na2O7S3 and a molar mass of 634.02 g/mol. Its CAS registry number is 5850-73-7. The IUPAC name is disodium, 5-chloro-4-hydroxy-3-[[4-(6-methyl-1,3-benzothiazol-2-yl)phenyl]diazenyl]naphthalene-2,7-disulfonate.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
disodium, 5-chloro-4-hydroxy-3-[[4-(6-methyl-1,3-benzothiazol-2-yl)phenyl]diazenyl]naphthalene-2,7-disulfonate
CAS number
5850-73-7
EC number
611-678-8
Molecular formula
C24H14ClN3Na2O7S3
UNII
6B08RLS632
InChIKey
SAQDWUFFHMEATC-UHFFFAOYSA-L
InChI
InChI=1S/C24H16ClN3O7S3.2Na/c1-12-2-7-18-19(8-12)36-24(26-18)13-3-5-15(6-4-13)27-28-22-20(38(33,34)35)10-14-9-16(37(30,31)32)11-17(25)21(14)23(22)29;;/h2-11,29H,1H3,(H,30,31,32)(H,33,34,35);;/q;2*+1/p-2
SMILES (canonical and isomeric)
CC1=CC2=C(C=C1)N=C(S2)C3=CC=C(C=C3)N=NC4=C(C5=C(C=C(C=C5C=C4S(=O)(=O)[O-])S(=O)(=O)[O-])Cl)O.[Na+].[Na+]

Synonyms

  • Fenamin pink B
  • Phenamine pink BT
  • Erie pink 2B
  • Rose BD
  • Direct pink bta-cf
  • Diaphtamine pink BN
  • Azine brilliant rose BD
  • C.i. direct Red 20
  • Nippon brilliant rose BD
  • Kayaku direct brilliant rose BD
  • Akiriku direct brilliant rose BD
  • C.i. direct Red 20, disodium salt
  • CI 15075
  • C.I. 15075
  • 2,7-Naphthalenedisulfonic acid, 5-chloro-4-hydroxy-3-(2-(4-(6-methyl-2-benzothiazolyl)phenyl)diazenyl)-, sodium salt (1:2)
  • disodium, 5-chloro-4-hydroxy-3-[[4-(6-methyl-1,3-benzothiazol-2-yl)phenyl]diazenyl]naphthalene-2,7-disulfonate
  • 2,7-Naphthalenedisulfonic acid, 5-chloro-4-hydroxy-3-[2-[4-(6-methyl-2-benzothiazolyl)phenyl]diazenyl]-, sodium salt (1:2)

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
634.02 g/molcalc.
Exact mass
632.9478 Dacalc.
LogP (octanol/water)
0.02calc.
Topological polar surface area
172.2 Ųcalc.
Hydrogen bond donors
1calc.
Hydrogen bond acceptors
11calc.
Rotatable bonds
5calc.
Heavy atoms
40calc.
Rings
5calc.
Aromatic rings
5calc.
Fraction sp3 carbons
0.04calc.
Formal charge
0calc.
Stereocentres
0calc.
Components
3calc.
Lipinski rule of five
Fails (2 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccc2cc(N=Nc3ccc(-c4nc5ccccc5s4)cc3)ccc2c1

c1ccc2cc(N=Nc3ccc(-c4nc5ccccc5s4)cc3)ccc2c1

5 rings, 27 atoms.

9 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

No GHS hazard classification is recorded for this substance yet. That does not mean it is harmless.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Direct Red 20 suppliers

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Direct Red 20 price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Industries and functions

Regulatory status

Inventories, regulations and trade controls that list this substance

No regulatory list memberships are recorded for this substance yet. Always check the rules of the importing and exporting country before trade.

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Direct Red 20 is traded under.

HS 3204.14Indicative HS code

Direct dyes and preparations based thereon

World exports in 2024
$328M
−1.5% vs 2023, imports $336M
2019 to 2024
Top exporters
  1. India * partner reported34.9%
  2. China11.3%
  3. Spain9.0%
Top importers
  1. Italy9.8%
  2. Germany8.7%
  3. Netherlands7.8%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Direct Red 20 is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Direct Red 20, based on the data on this page

What is Direct Red 20?

Direct Red 20 is a chemical substance with the molecular formula C24H14ClN3Na2O7S3 and a molar mass of 634.02 g/mol. Its CAS registry number is 5850-73-7. The IUPAC name is disodium, 5-chloro-4-hydroxy-3-[[4-(6-methyl-1,3-benzothiazol-2-yl)phenyl]diazenyl]naphthalene-2,7-disulfonate.

What is the CAS number of Direct Red 20?

The CAS registry number of Direct Red 20 is 5850-73-7.

What is the molecular formula and weight of Direct Red 20?

The molecular formula of Direct Red 20 is C24H14ClN3Na2O7S3 and its molar mass is 634.02 g/mol.

What is Direct Red 20 used for?

Known uses and roles of Direct Red 20 include textile dyes in textiles and leather.

Is Direct Red 20 hazardous?

No GHS hazard classification for Direct Red 20 is recorded on CompoundList yet. That does not prove it is safe. Always read the supplier safety data sheet.

What is the HS code of Direct Red 20?

Direct Red 20 is usually classified under HS code 320414 (Direct dyes and preparations based thereon). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Direct Red 20?

Post a free request on CompoundList and suppliers of Direct Red 20 will send you quotes. Your contact details stay private until you accept a quote.

What is the price of Direct Red 20?

Suppliers quote Direct Red 20 on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Direct Red 20

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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