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Vitamin K7.svg
Preferred IUPAC name
3D model (JSmol)
ECHA InfoCard 100.001.360 Edit this at Wikidata
EC Number
  • 201-495-8
  • InChI=1S/C11H11NO/c1-7-6-10(13)8-4-2-3-5-9(8)11(7)12/h2-6,13H,12H2,1H3
  • CC1=C(C2=CC=CC=C2C(=C1)O)N
Molar mass 173.215 g·mol−1
Appearance crystalline (HCl)[1]
Melting point 270 °C[1] HCl decays
HCl is soluble[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

4-amino-3-methyl-1-naphthol is a synthetic menadione analog. It is also known as vitamin K7,[1] and was named as such in 1950 when it was recognized as a compound with vitamin K activity.[2][3]

It can be made from 2-methylnaphthalene or menadione. It forms a crystalline hydrochloride salt (C11H11NO·HCl) from hydrochloric acid. At least 1 g of the salt dissolves in 25 ml of water at 75 °C. The salt turns pink to dark violet on exposure to air and light.[1]

4-Amino-3-methyl-1-naphthol or its hydrochloride have not been used as commercial medicinal forms of vitamin K unlike phylloquinone and menadione for example.[4]


  1. ^ a b c d e Budavari S, et al. (2000). The Merck index (12th ed.). Chapman & Hall Electronic Pub. Division. p. 1581. ISBN 9781584881292.
  2. ^ Sah PP (1949–1950). "Synthesis of 3-methyl-4-amino-1-naphthol hydrochloride (vitamin K7) and related vitamin-K-active compounds". Zeitschrift für Vitamin-, Hormon- und Fermentforschung. 3 (3–4): 324–345. ISSN 0373-0220. PMID 14782638.
  3. ^ Dam H (1951). "Fat-soluble vitamins". Annual Review of Biochemistry. 20 (1): 265–304. doi:10.1146/annurev.bi.20.070151.001405. PMID 14847531.
  4. ^ Fiore LD, et al. (2001). "Anaphylactoid reactions to vitamin K". Journal of Thrombosis and Thrombolysis. 11 (2): 175–183. doi:10.1023/A:1011237019082. ISSN 1573-742X. PMID 11406734. S2CID 975055.