A Practical Synthetic Method of O-(2-(Pyrazol-1-yl)pyridin-5-yl)methylhydroxylamine as a Component of Modithromycin
摘要:
A practical synthesis of O-(2-(pyrazol-1-yl)pyridin-5-yl)methylhydroxylamine was achieved from the inexpensive raw materials, 2-chloro-5-chloromethylpyridine, pyrazole, and acetone oxime, using common reagents such as aq NaOH and sulfuric acid.
A compound having the formula (1): can be produced with efficiency by using a compound represented by the formula (2): wherein R represents a protected hydroxyl group or a group represented by the formula (3): where R
1
represents an alkyl group or an aralkyl group which may be substituted; and R
2
represents an alkyl.
The present invention relates generally to novel methods for the synthesis of O-(6-pyrazol-1-yl-pyridin-3-ylmethyl)-hydroxylamine which is an essential reagent in the synthesis of one of the bridged erythromycin derivatives and their respective pharmaceutically acceptable salts in PCT Application WO 03/097659 A1. In particular, the present invention relates to processes and intermediates for the preparation of a compound of formula (Ia):
Inventors found that a compound shown by formula:
can be produced efficiently by using a compound shown by formula:
(wherein R is a protected hydroxy or a group shown by:
(wherein R1 is alkyl or optionally substituted aralkyl, and R2 is alkyl)).
发明者发现,一种化合物如式所示:
式所示的化合物可以高效生产:
(其中 R 是受保护的羟基或以下所示的基团
(其中 R1 为烷基或任选取代的芳基,R2 为烷基))。