FIELD: chemistry.
SUBSTANCE: invention relates to a method of producing 6,7-substituted-2,3,5,8-tetrahydroxy-1,4-naphtoquinones (spinazarins) of formula (I), where R1 and R2 both simultaneously denote H, ME, Cl or R1=H, and R2=Me, Et, t-Bu, CI, OMe; R1=Me, and R2=CI, OMe, OEt, OH; R1=Et, and R2=CI, OMe, OEt, OH, which can be used in medicine and cosmetology, as well as intermediate compounds used in said method. The disclosed method comprises the following steps: a) reaction of 6,7-substituted compounds of formula II, 
where R1 and R2 are defined above, with excess sodium nitrite to obtain a compound of formula III, 
where R1 and R2 both simultaneously denote H, Me, Cl; or R1=H, and R2=Me, Et, t-Bu, CI, OMe; or R2=H, and R1=Me, Et, t-Bu, CI, OMe; or R1=Me, and R2=CI, OMe, OEt; or R2=Me, and R1=CI, OMe, OEt, OH; or R1=Et, and R2=CI, OMe, OEt; or R2=Et, and R1=CI, OMe, OEt, OH, where for compounds where R1≠R2, a mixture of isomers is usually formed; b) reaction of the compound of formula III with a reducing agent to form a compound of formula IV, 
where R1 and R2 are defined above; c) converting the compound of formula IV obtained from reduction via acid-catalyst hydrolysis into a compound of formula I 
EFFECT: method enables to obtain end products in mild conditions using readily available and cheap reagents.
2 dwg, 49 ex
