- A process for synthesizing phenylbutyric acid nitrogen mustard antineoplastic agent
-
The invention relates to a synthesis process of an antineoplastic drug chlorambucil. The synthesis process comprises the following steps: (1) amino protection reaction; (2) acylation reaction; (3) reduction reaction; (4) carboxyl protection reaction; (5) substitution reaction; (6) chlorination reaction; and (7) deprotection reaction. According to the synthesis process, the amino group is protected by use of acetic anhydride, and then acylation, reduction, carboxyl protection, substitution, chlorination and aqueous hydrochloric acid solution hydrolysis are performed to obtain the chlorambucil. The synthesis process of the antineoplastic drug chlorambucil has the characteristics of low cost, mild reaction conditions, low toxicity, convenience in process operation, and suitability for industrial production.
- -
-
-
- Aldolase antibodies of remarkable scope
-
This paper describes the substrate specificity, synthetic scope, and efficiency of aldolase catalytic antibodies 38C2 and 33F12. These antibodies use the enamine mechanism common to the natural Class I aldolase enzymes. Substrates for these catalysts, 23 donors and 16 acceptors, have been identified. The aldol acceptor specificity is expected to be much broader than that defined here since all aldehydes tested, with the exception polyhydroxylated aldehydes, were substrates for the antibodies. 38C2 and 33F12 have been shown to catalyze intermolecular ketone-ketone, ketone- aldehyde, aldehyde-ketone, and aldehyde-aldehyde aldol addition reactions and in some cases to catalyze their subsequent dehydration to yield aldol condensation products. Substrates for intramolecular aldol reactions have also been defined. With acetone as the aldol donor substrate a new stereogenic center is formed by attack on the si-face of the aidehyde with ee's in most cases exceeding 95%. With hydroxyacetone as the donor substrate, attack occurs on the re-face, generating an (α,β-dihydroxy ketone with two stereogenic centers of the α-syn configuration in 70 to >98% ee. With fluoroacetone donor reactions, the major product is a syn α-fluoro-β- hydroxy ketone with 95% ee. Studies of retroaldol reactions demonstrate that the antibodies provide up to 108-fold enhanced efficiency relative to simple amine-catalyzed reactions.
- Hoffmann, Torsten,Zhong, Guofu,List, Benjamin,Shabat, Doron,Anderson, James,Gramatikova, Svetlana,Lerner, Richard A.,Barbas III, Carlos F.
-
p. 2768 - 2779
(2007/10/03)
-