| 摘要 |
<p>There are prepared compounds of the formula <IMAGE> where R and R1 are saturated and preferably linear alkyl groups in which the sum of carbon atoms in the two alkyl groups is 4 to 30, ONE OF R and R1 can also be hydrogen, R2 is hydrogen or if R3 is hydrogen, then R2 is the group <IMAGE> where n is 1 to 10, R3 is hydrogen or, if R2 is hydrogen, then R3 is the group <IMAGE> and R4 is hydrogen or methyl.</p> |
