Reaction #2298619

Reaction equation

ammonium formate

3-(formylamino)-2-thiophenecarboxylic acid methyl ester

3-(Formylamino)-2-thiophenecarboxylic acid methyl ester

→

3H-thieno[3,2-d]pyrimid-4-one

Yield 63.4%

Solvents

formamide

Conditions

Workup

1. 1
   OtherThe precipitate that formed
2. 2
   Filtrationwas collected by vacuum filtration

Procedure

To a solution of ammonium formate (9.4 g, 0.15 mol) in formamide (14 mL) at 150° C. was added 3-(formylamino)-2-thiophenecarboxylic acid methyl ester (81, 5.2 g, 28 mmol) as a solid in small portions. The resulting solution was heated at 150° C. for 4 hours and then allowed to stand at room temperature for 12 hours. The precipitate that formed was collected by vacuum filtration to give 3H-thieno[3,2-d]pyrimid-4-one (2.7 g, 63% yield) as white needles.

Source