Methyl 6-chloropyridine-3-carboxylate → 3-Methyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-7-carboxylic acid, methyl ester
Reaction equation
[NH2:1][C:2]1[S:3][CH:4]=[C:5]([CH3:11])[C:6]=1[C:7](OC)=[O:8].Cl[C:13]1[N:18]=[CH:17][C:16]([C:19]([O:21][CH3:22])=[O:20])=[CH:15][CH:14]=1>>[CH3:11][C:5]1[C:6]2[C:7](=[O:8])[N:18]3[CH:17]=[C:16]([C:19]([O:21][CH3:22])=[O:20])[CH:15]=[CH:14][C:13]3=[N:1][C:2]=2[S:3][CH:4]=1Participants
3
Procedure
A mixture of 11.27 g (0.066 mol) of 2-amino-4-methyl-3-thiophenecarboxylic acid, methyl ester (Chemische Berichte, Vol. 98, pages 3571-3577, 1965) and 11.3 g (0.066 mol) of 6-chloro-3-pyridinecarboxylic acid, methyl ester (Alfred Bader Chemical Company) is heated in a wax bath at 173°-190° C. for 220 minutes under nitrogen. The distillate is collected in a Dean-Stark trap attached to the reaction flask. The mixture is cooled, dissolved in hot methanol, cooled and 0.61 g of 3-methyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-7-carboxylic acid, methyl ester is collected; mp 208°-209° C. after recrystallization from dichloromethane-methanol.
Workup
- temperatureis heated in a wax bath at 173°-190° C. for 220 minutes under nitrogen
- distillationThe distillate is collected in a Dean-Stark trap
- temperatureThe mixture is cooled
- dissolutiondissolved in hot methanol
- temperaturecooled
- custom0.61 g of 3-methyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-7-carboxylic acid, methyl ester is collected
- custommp 208°-209° C. after recrystallization from dichloromethane-methanol
Sources & evidence
- ORD record
- ord-8935e0c013e14ff28f55b63d0e458818
- Source dataset
- uspto-grants-1982_06
- Patent number
- US04332947
Reaction notes
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