6-Chloronicotinic acid → 2-Methyl-10-oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidine-7-carboxylic acid
Reaction equation
[NH2:1][C:2]1[CH:6]=[C:5]([CH3:7])[S:4][C:3]=1[C:8]([O:10]C)=O.Cl[C:13]1[N:18]=[CH:17][C:16]([C:19]([OH:21])=[O:20])=[CH:15][CH:14]=1>CO>[CH3:7][C:5]1[S:4][C:3]2[C:8](=[O:10])[N:18]3[CH:17]=[C:16]([C:19]([OH:21])=[O:20])[CH:15]=[CH:14][C:13]3=[N:1][C:2]=2[CH:6]=1Participants
4
Procedure
A mixture of 1.7 g (0.01 mol) of 3-amino-5-methyl-2-thiophenecarboxylic acid, methyl ester (German Pat. No. 1055007, Apr. 16, 1959) and 1.6 g (0.01 mol) of 6-chloro-3-pyridinecarboxylic acid (Aldrich Chemical Company) is heated in an oil bath at 180° C. for two hours. The mixture is cooled, dissolved in hot methanol, cooled and 0.23 g of 2-methyl-10-oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidine-7-carboxylic acid is collected; mp 338°-340° C. after recrystallization from methanol.