Preparation of Amino-2,6-Naphthyridines

Many amino-1,5-naphthyridines have been made by primary synthesis (see Chapter 1), by aminolysis of halogeno-1,5-naphthyridines (see Section 3.2.2), or by aminolysis of 1,5-naphthyridinones (see Section 4.1.2). Others have been made by direct amination, as illustrated in the following examples. 

Note A definitive procedure for the amination of 1,5-naphthyridine has been given in Section 2.1.3, along with references to its vexed history. 

3-Nitro-l,5-naphthyridine (10, R = H) gave 3-nitro-l,5-naphthyridin-4-amine (10, R = NH2) (substrate, liquid NH3 [, KMn04 [ portionwise then 15 min 74%) 3-nitro-l,5-naphthyridin-2-amine (11, R = H) gave 3-nitro-l,5-naphthyridine-2,4-diamine (11, R = NH2) (likewise 33%) and 3-nitro-l,5-naphthyridin-2(17/)-one (12, R = H) gave 4-amino-3-nitro-l,5-naphthyridin-2 (l//)-one (12, R = NH2) (likewise 51%).818 

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