| 摘要 |
They have the formula: <IMAGE> (I) where either R1 and R2 are identical and represent -CH2R where R=H or a C1 to C4 alkyl group or R1 and R2 together form the -CH2(CR4R4)n-CH2 group where n=0 or 1, R4 =H or -CH3, R3=H or -CH2R5 where R5=H or a C1 to C4 alkyl group. A and A1 are either identical and represent H or A and A1 together form an ethylene, trimethylene or -CH(OCH2R6)-CH(OCH2R6)- radical where R6=H or a C1 to C4 alkyl group or, when R3=H, a 1,2 dihydroxy-ethylene group. They are obtained by reacting a disubstituted ethanal <IMAGE> (II) with a urea ANH-CO-NHA, followed if required by etherification with an alcohol R5CH2OH. |
