2-Methylnaphthalene-1,4-diamine explained

2-Methylnaphthalene-1,4-diamine is a synthetic menadione analog with vitamin K activity.^{[1] [2]}

2-Methylnaphthalene-1,4-diamine was first synthesized in 1925.^{[3] [1]} In 1942 two different research groups noted the vitamin K activity of the compound.^{[1] [4] [5]} It forms a dihydrochloride salt (C₁₁H₁₄Cl₂N₂) with hydrochloric acid and one of the aforementioned research groups suggested the name vitamin K₆ for the salt.^[1]

2-Methylnaphthalene-1,4-diamine and its dihydrochloride can be made from 2-methylnaphthalene or its close analogs. Dihydrochloride blackens without melting at about 300 °C.^[1]

4-Amino-3-methyl-1-naphthol or its dihydrochloride have not been used as commercial medicinal forms of vitamin K unlike phylloquinone and menadione for example.^[6]

Oral toxicity of dihydrochloride for rats is approximately the same as for 4-amino-2-methyl-1-naphthol hydrochloride.^[1]

Notes and References

1. Veldstra H, Wiardi PW. 1943. Water soluble antihemorrhagic substances I: synthesis of 2-methyl-4-aminonaphthol-1 hydrochloride and of 2-methyl-1,4-diaminonaphthalene dihydrochloride, the water soluble synthetic vitamins K5 and K6. Recueil des Travaux Chimiques des Pays-Bas. 62. 2. 75–84. 10.1002/recl.19430620203. 0165-0513.
2. Book: The Merck index. Budavari S. Chapman & Hall Electronic Pub. Division. 2000. 9781584881292. 12th. 1581. etal.
3. Veselý V, Kapp J. 1925. Sur les dérivés nitres du méthyl-2-naphtalène. Recueil des Travaux Chimiques des Pays-Bas. 44. 4. 360–375. 10.1002/recl.19250440409. 0165-0513.
4. Baker BR, Carlson GH. 1942. Water-soluble compounds with antihemorrhagic activity. Journal of the American Chemical Society. 64. 11. 2657–2664. 10.1021/ja01263a038. 0002-7863.
5. Robinson FA, Holland DO. 1948. Preparation of water-soluble derivatives of 2-methylnaphthalene. Journal of the Chemical Society. 2. 182–186. 10.1039/JR9480000182. 18906382. 0368-1769.
6. etal. Fiore LD. 2001. Anaphylactoid reactions to vitamin K. Journal of Thrombosis and Thrombolysis. 11. 2. 175–183. 10.1023/A:1011237019082. 1573-742X. 11406734. 975055.