| 摘要 |
The invention describes a method of synthesizing a compound of the formula <IMAGE> (I) in which X=O or NR, Z=an electron-attracting group, R=H, CN or NO2, R1 +R2+N-C=X=a 5-membered or 6-membered heterocycle, and R3=H, R4=OH or R3+R4=a bond, said method involving intermediates of the formula <IMAGE> (IX) in which R5=H, Br or N(R1)CXR2. This method of synthesis does not involve the epoxide derivative of the chroman. The novel compounds of formula (IX) form a further subject of the invention.
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