1086838-13-2

1086838-15-4

1086838-13-2

The general procedure for the synthesis of 5-chloro-3-nitropyridine-2-carbaldehyde from the compound (CAS:1086838-15-4) is as follows: first, 2-amino-3-(6-chloro-3-methoxy-2H-pyrazolo[4,3-b]pyridin-2-yl)-2-methylpropanenitrile (39 mg) was prepared in quantitative amounts according to a method similar to that described in the preceding. Referring to the operation of Example 1 part b, but using 1-(6-chloro-3-methoxy-2H-pyrazolo[4,3-b]pyridin-2-yl)propan-2-one (32 mg) as a starting material. 1-(6-chloro-3-methoxy-2H-pyrazolo[4,3-b]pyridin-2-yl)propan-2-one was prepared similarly as described in Example 105. Next, the method of Example 136 parts a to d was followed, but using 5-chloro-3-nitropyridine-2-carboxaldehyde (1.2 g) and decaborane from part a to prepare [2-(tert-butyldimethylsilyloxy)propyl]-(5-chloro-3-nitropyridin-2-yl)methanamine (0.4 g in 17% yield). 5-chloro-3-nitropyridine-2-carboxaldehyde was prepared similarly to that described in Example 136 parts a to c, with the difference that one starts with 2-amino-5-chloro-3-nitropyridine in part a or uses commercially available 2-bromo-5-chloro-3-nitropyridine as a starting material for part b. The method of preparing 5-chloro-3-nitropyridine-2-carbaldehyde is similar to that described in Example 136 parts a to c. Additionally, the ozonolysis step of part c can be replaced by oxidative cracking using a 4% aqueous osmium tetroxide solution (2 mL) and sodium periodate (1.2 g) in a mixture of THF and water (10:1, 20 mL). Finally, 5-chloro-3-nitro-2-vinylpyridine (1 g) was prepared from 5-chloro-3-nitropyridine-2-carbaldehyde (0.72 g, 72% yield) with reference to the method of Example 61.