| 摘要 |
FIELD: organic chemistry, chemical technology. ^ SUBSTANCE: invention relates to compounds of the formula (I) wherein R1 means hydrogen or chlorine atom; R2 means hydrogen atom, (C1-C8)-alkyl or (C1-C8)-alkyl substituted with (C1-C6)-alkoxy- or (C3-C6)-alkenyloxy-group. These compounds can be synthesized by carrying out the following stages: a) addition of the main portion of the amount of compound of the formula (II) given in the claimed invention that must interact and a mixture of solvents including at least one organic solvent able to form azeotrope with water and at least one aprotonic bipolar solvent; b) dosing in a strong base taken in the amount equivalent with the main portion of the total amount of this compound of the formula (II); c) addition of remaining portion of the amount of compound of the formula (II) that must interact; d) addition of a weak base in the amount that is at least equivalent with this remaining portion; e) removal of water from the reaction mixture by azeotropic distillation; f) addition of compound of the formula (III) given in the claimed invention wherein radical R2 has the same values as given for compound of the formula (I); g) isolation of synthesized compound of the formula (I) from the reaction mixture. Invention provides increasing yield and enhanced quality of the end product. ^ EFFECT: improved preparing method. ^ 2 cl, 1 tbl, 1 ex |
