| 摘要 |
<p>Intermediates of formula
and processes for their preparation are provided. The process comprises reacting a compound of formula R 1 -CO-CH 2 -E with a compound of formula R 2 -CHX 1 X 2 in the presence of a compound of formula R 3 R 4 N-C(=NH)NH 2 and a catalyst. R 1 is H or an alkyl group; R 2 is H, an alkyl or aryl group; R 3 and R 4 are each independently H, alkyl or aryl, or R 3 and R 4 are linked to form, together with the nitrogen to which they are attached to form a 5 to 7 membered heterocyclic ring; E is H, an unsubstituted alkyl group, an aryl group or an electron withdrawing group; and X 1 and X 2 are each independently leaving groups, or X 1 and X 2 together represent =O.</p> |
