Thieno[2,3-d]pyrimidin-4(3H)one

Brown Solid

A solution of methyl 2-aminothiophene-3-carboxylate (3.0 g, 19.1 mmol) in formamide (95 ml) was heated at 190° C. for 4 hours. The cooled mixture was poured into water. The precipitate was filtered off, washed with water and dried. The crude product was purified by silica gel chromatography (CHExample 304 Example 304 2-aminothiophene-3-carboxylic acid methyl ester (4.7 g, 30 mmol) was added to a 250 mL round bottom flask.Ammonium formate (6.3g, 100mmol) and 25mL formamide, The mixture was heated at 150 °C with stirring for 6 h.After the reaction was completed, it was stored at 0°C for 24 hours and suction filtered to give a brown solid (2.8 g, 58percent).The synthesis was carried out according to the procedure of Jang et al.Thieno[2, 3-d]pyrimidin-4(3H)-one (2). Methyl 2-aminothiophene-3-carboxylate (1) (26.0 g, 165 mmol) was mixed with formamide (285 mL) and heated at 215 °C for 5 h. The reaction mixture was then cooled to rt. and water (500 mL) was added, followed by extraction with EtOAc (4 x 500 mL). The combined organic fractions were dried over NaMethyl 2-aminothiophene-3- carboxylate (10 g, 64 mmol) was charged with formamide (50 mL). The reaction was heated at 190 °C under nitrogen for 3 hours, then cooled to ambient temperature. The resulting slurry was poured into 125 mL of water and extracted with chloroformdsopropyl alcohol mixture (2 times). The solution was concentrated and triturated to afford the title compound (2.25 g, 23percent).Under an argon atmosphere, 118 mL of formamide was added to 7.83 g of methyl 2-aminothiophene-3-carboxylate, The mixture was stirred at 200 ° C. for 4 hours, The temperature was returned to room temperature.Water was added and the mixture was extracted 9 times with ethyl acetate, The organic layer was dried over anhydrous sodium sulfate, After filter paper filtering, The solvent was distilled off under reduced pressure. The solid obtained was subjected to decantation with ethyl acetate 8 times, washed and dried under reduced pressure to give 3.45 g of the title compound as a brown solid.250 mL of a three-necked flask, A solution of methyl 2-aminothiophene-3-carboxylate (20 g, 0.127 mol) and formamidine acetate (30 g, 0.29) was dissolved in ethanol at 80 °C for 24 hours and the reaction was complete until the reaction was complete. After the reaction solution was cooled, the mixture was stirred in water, The precipitated solid was filtered and the cake was dried to obtain 15 g of soil yellow powder in a yield of 77.7percent.General procedure: The different ethyl 2-aminothiophene-3-carboxylate (5a-g) (1 eq.) and formamide (3.2mL/mmol eq.) were refluxed for 8 h. The reaction mixture was then cooled in an ice-bath and added of cold water. The precipitate formed was collected by filtration, washed thoroughly with cold water and purified by crystallisation from EtOH/H2O unless otherwise stated.

Molecular Weight:152.18
XLogP3:0.7
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Exact Mass:152.00443393
Monoisotopic Mass:152.00443393
Topological Polar Surface Area:69.7
Heavy Atom Count:10
Complexity:192
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes