Reactions With 2-Amino-3,5-Dicyanopyridines

M Seada, M. A. El Behairy, H. Jahine And F. Hanafy

Faculty of Education, Ain Shams University, Roxy, Cairo Egypt.

2-Amino-4-(p-anisyl)-3, 5-dicyano-6-methoxypyridine (Ia) reacted with hydrazine hydrate yielding 3, 6-diamino-4-(p-anisyl)-5-cyanopyrazolo [3, 4-b] pyridine (Ha). Treatment of Ila with formaldehyde afforded 1-hydroxymethyl-4. 6-diamino-4-( p-anisyl )~5-cyanopyrazolo [ 3, 4-b ] pyridine (lIb), which on heating with morpholine in DMF gave Mannich base (IIc). Reaction of Ila with dimethyl sulphate or ethyl bromoacetate gave the N-alkylated products (IId) and (IIe), respectively, lie on treatment with hydrazine hydrate or p-toluidine gave the corresponding hydraride (Ilf) and p-toluidine (Ilg), respectively. The condensation of llf with aromatic aldehyhes gave the arylidenehydrazides (llh-i). The reaction of triethylorthoformate with la or Ilf led to the formation of bis-[2-imino-4~(p-anisyl)-3, 5-dicyano-6-methoxypyridine] ethoxyrnethane (III) and l-[ 2'-methylene-4'-acetyl-5'-ethoxy )-Δ2'-1,3 4'-oxadiazoline ]-3-acetamido-6-amino-4-(p-anisyI)-5-cyano-pyrazoIo [3, 4-b] pyridine IV, respectively. Ilf reacted with succinic anhydride in glacial acetic acid yielding (V). The reaction of la or Ila with ethyl cyanoacetate in the prese¬nce of sodamide gave 4-amino-"5-(p-anisyl)-3, 6-dicyano-l, 2,-dihydro-7-methoxy-l,8-naphthyridin-2-one (Via) and VII respectively. Treatment of la with acetic anhydride in the presence of phosphoric acid afforded 2-acetamido-4-(p-anisyI)-3, 5-dicyano-6~methoxy-pyridine (IbX which was readily cyclized on treatment with sodaamide in DMF to form 4-amino-5-(p-anisyI)-6-cyano-l, 2-dihydro-7-methoxy-1, 8-naphthyridin-2-one (VIb). Cyanoethylation of la or Ila with acrylonitrile gave Ic and IIj. respectively. Hydrolysis of Ic and IIj with HC1 gave the corresponding acids Id and Ilk, respectively. Treatment of la with formamide or urea afforded VIII and IX, respectively. The reaction cf la with arylmagnesium halides gave the corresponding anil derivatives (Xa—b). Fusion of Xa or Xb with hydrazine hydrate afforded pyrazolo {3, 4 b] pyridine derivatives XIa and Xlb respectively.

Reactions; 5-Dicyanopyridines