91431-42-4

Lonapalene,Syntex

Antipsoriatic.

ChEBI: Lonapalene is an organochlorine compound and a member of naphthalenes.

A solution of sodium nitrate (0.69 g, 10 mmol) in water (5 ml) was added at 0-5°C to a solution of 6-amino-2,3-dimethoxy-1,4-naphthoquinone (1.17 g, 5 mmol) in 5:1 acetic acid:water (25 ml) containing concentrated hydrochloric acid (1.7 ml). A further quantity of sodium nitrite (0.69 g) was then added to the reaction mixture after cooling to -5°C, followed by a solution of cuprous chloride (0.6 g) in concentrated hydrochloric acid (5 ml). The mixture was allowed to warm to room temperature and solid cuprous chloride was added portionwise until the mixture assumed a green color. Water was then added to the reaction mixture and the precipitated yellow solid filtered off, washed with water and recrystallized from methanol:water (2:1) giving 1.01 g of 6-chloro- 2,3-dimethoxy-1,4-naphthoquinone, melting point 93-94°C (from etherpetrolium ether).

Antipsoriatic