Article · Wikipedia archive · Last revised Jul 19, 2026

Dichlone

Dichlone is a fungicide and algicide of the quinone class. It is a general use fungicide applied to fruits, vegetables, field crops, ornamentals, and residential and commercial outdoor areas. It is also used to control blue algae.

Last revised
Jul 19, 2026
Read time
≈ 1 min
Length
230 w
Citations
7
Source
Wikipedia ↗
Dichlone
source ↗
Names
Preferred IUPAC name
2,3-Dichloronaphthalene-1,4-dione
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.003.828
EC Number
  • 204-210-5
UNII
UN number 2902 2761
  • InChI=1S/C10H4Cl2O2/c11-7-8(12)10(14)6-4-2-1-3-5(6)9(7)13/h1-4H
    Key: SVPKNMBRVBMTLB-UHFFFAOYSA-N
  • C1=CC=C2C(=C1)C(=O)C(=C(C2=O)Cl)Cl
Properties
C10H4Cl2O2
Molar mass 227.04 g·mol−1
Appearance Yellow crystals1
Melting point 193 °C (379 °F; 466 K)1
0.1 ppm1
Hazards
GHS labelling:[1]
GHS07: Exclamation markGHS09: Environmental hazard
Warning
H302, H315, H317, H319, H410
P261, P264, P264+P265, P270, P272, P273, P280, P301+P317, P302+P352, P305+P351+P338, P321, P330, P333+P317, P337+P317, P362+P364, P391, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Dichlone (trade names Phygon and Quintar) is a fungicide and algicide of the quinone class. It is a general use fungicide applied to fruits, vegetables, field crops, ornamentals, and residential and commercial outdoor areas.1 It is also used to control blue algae.2

Dichlone is not persistent in soil and has moderate mammalian toxicity.2

Dichlone can be manufactured by the chlorination and oxidation of naphthalene.3

Synthesis of dichlone from naphthalene source ↗
References

References

  1. "Dichlone (Phygon, Quintar) Chemical Profile". Pesticide Management Education Program, Cornell Cooperative Extension.
  2. "Dichlone". Pesticide Properties DataBase, University of Hertfordshire.
  3. Thomas A. Unger (1996). Pesticide Synthesis Handbook. William Andrew. p. 966. ISBN 0-8155-1853-6.