Ethyl Thioglycolate → 3-Hydroxy-thieno[3,2-c]pyridine-2-carboxylic acid ethyl ester

Temperature

5 °C

To a cooled (5° C.) stirred solution of ethyl 4-chloro-nicotinate (1.55 g, 8.4 mmol) and mercapto-acetic acid ethyl ester (2.6 ml, 23.4 mmol) in anhydrous DMF (30 ml), under an argon atmosphere, was added sodium hydride (21.7 mmol; 60% dispersion in oil, 868 mg) in portions over 20 minutes. Stirring was continued at 5° C. for 10 minutes, followed by 1.5 hours at room temperature. The reaction mixture was then quenched by the addition of water (5 ml), acidified by the addition of acetic acid (1 ml), and subsequently concentrated to provide a residue. The residue was partitioned between ethyl acetate (150 ml) and water (100 ml). The layers were separated and aqueous phase was extracted with DCM (100 ml). The combined organic phase was dried over sodium sulphate, filtered and evaporated to give a solid. The solid was triturated with diethyl ether:pentane (1:1, 15 ml) to afford the title compound as a yellow solid (1.5 g, 81%). LCMS (method B): RT=2.21 min, M+H+=224.

1. waitfollowed by 1.5 hours at room temperature
2. customThe reaction mixture was then quenched by the addition of water (5 ml)
3. additionacidified by the addition of acetic acid (1 ml)
4. concentrationsubsequently concentrated
5. customto provide a residue
6. customThe residue was partitioned between ethyl acetate (150 ml) and water (100 ml)
7. customThe layers were separated
8. extractionaqueous phase was extracted with DCM (100 ml)
9. dry with materialThe combined organic phase was dried over sodium sulphate
10. filtrationfiltered
11. customevaporated
12. customto give a solid
13. customThe solid was triturated with diethyl ether:pentane (1:1, 15 ml)

ORD record

ord-a331b002bd3848d1b488ad005af465c5

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07893085B2