|Title:||Process for preparing an A2A-adenosine receptor agonist and its polymorphs|
|Abstract:|| Disclosed is a synthesis suitable for large scale manufacture of an A.sub.2A-adenosine receptor agonist, and also relates to polymorphs of that compound, and to methods of isolating a specific polymorph.|
|Inventor(s):|| Zablocki; Jeff (Mountain View, CA), Elzein; Elfatih (Fremont, CA) |
|Assignee:|| Gilead Sciences, Inc. (Foster City, CA) |
|Filing Date:||Jan 13, 2010|
|Claims:||1. A method of synthesizing a compound of the formula (4): ##STR00025## comprising contacting a compound of the formula (2): ##STR00026## with an excess of ethyl 2-formyl-3-oxopropionate optionally in the presence of acid. |
2. The method of claim 1, wherein the contacting is conducted in ethanol.
3. The method of claim 1, wherein the acid is HCl up to 0.1 molar equivalent is used.
4. The method of claim 3, wherein the contacting takes place at reflux.
5. The method of claim 1, wherein about a 5-10 fold molar excess ethyl 2-formyl-3-oxoproionate is used.
6. The method of claim 5, wherein about a 6.8-7.5 fold molar excess of ethyl 2-formyl-3-oxoproionate is used.
7. The method of claim 6, wherein the compound of the formula (4) is isolated by (a) cooling the completed reaction mixture to approximately 10.degree. C., (b) filtering, (c) washing the contents of the filter with ethanol, and (d) drying the solid that remains under vacuum at a temperature that does not exceed 40.degree. C.