FIELD: organic chemistry, medicine. SUBSTANCE: invention relates to method of treatment of diseases that can be relieved by inhibition of tyrosine kinase receptor VEGF or by inhibition of angiogenesis. Method involves administration of phthalazine derivatives of the formula (I) 
, the novel phthalazine derivatives of the formula (I), pharmaceutical composition comprising thereof and method for preparing compounds of the formula (I). Invention enhances the effectiveness of treatment and realizes the novel therapeutic approach with respect to treatment and prophylaxis of diseases indicated above. EFFECT: valuable medicinal properties of compounds. 16 cl, 7 tbl
