Processes for the preparation of O-(6-Pyrazol-1-yl-pyridin-3-ylmethyl)-hydroxylamine
The present invention relates to processes and intermediates for the preparation of 6–11 bicyclic erythromycin derivatives. In particular, the present invention relates to processes and intermediates for the preparation of a compound of formula (IX-c):
1. A process of preparing , a compound of formula (XI):
the process comprising the steps of:
(a) reacting pyrazole with methyl 6-cholonicotinate in the presence of a strong base to provide 6-pyrazole-1-yl-nioctinic acid methyl ester (compound of formula (XI-a));
(b) reducing the compound of formula (XI-a) prepared in Step (a) with a reducing agent to provide (6-pyrazole-1-yl-pyridin3-yl)-methanol (compound of formula (XI-b));
(c) halogenating the compound of formula (XI-b) prepared in Step (b) with a chlorinating agent to provide 5-chloromethyl-2-pyrazole-1-yl-pyridine (compound of formula (XI-c));
(d) adding the compound of formula (XI-c), prepared in Step (c) with a compound of formula (XI-e);
wherein A and B are both hydrogen or taken together with with th carbon atoms to which they are attached are selected from aryl, substituted aryl, heterocyclic, or substituted heterocyclic, to provide a compound of formula (XI-d);
and
(e) hydrolying a compound of formula (XI-d), prepared in Step (d), with a base.
2. The process of claim 1 , wherein for the step of reacting, the strong base is sodium hydride.
3. The process of claim 1 , wherein for the step of reducing, the reducing agent is sodium borohydride.
4. The process of claim 1 , wherein for the step of halogenating the chlorinating agent is thiony chloride.
5. The process of claim 1 , wherein in step (c) the base is ammonia.