Hydrochloric Acid → Methyl 5-nitro-1-benzothiophene-2-carboxylate

A 2000 ml 3-necked round-bottomed flask, 250 ml pressure equalized dropping funnel, Teflon stirrer, and gas inlet were oven-dried for 12 hours at 160° C. The apparatus was rapidly assembled, fitted with a thermometer, flushed with dry nitrogen gas, and allowed to cool to room temperature. The cooled flask was charged with methanol (600 ml) and methyl thioglycolate (28.6 g, 0.27 mole). Sodium methoxide (19,98 g, 0.37 mole) in methanol (125 ml) was added to the reaction mixture over 10 minutes while stirring. The reaction mixture was then warmed to 40° C. and a solution of 2-chloro-5-nitrobenzaldehyde (28.6 g, 0.27 mole) in methanol (300 ml) was added over a period of about 20 minutes. The resulting slurry was stirred at 40° C. for 1 hour, cooled to room temperature, and acidified with 2M hydrochloric acid. The resulting white solid was filtered, washed with water (2×300 ml) and air-dried to give 61 g (95%) of methyl 5-nitrobenzothiophene-2-carboxylate. See, R. A. Zambias, M. L. Hammond, Synthetic Communications, 21:959 (1991).

1. customA 2000 ml 3-necked round-bottomed flask, 250 ml pressure equalized dropping
2. customfunnel, Teflon stirrer, and gas inlet were oven-dried for 12 hours at 160° C
3. customfitted with a thermometer
4. customflushed with dry nitrogen gas
5. temperatureThe reaction mixture was then warmed to 40° C.
6. stirringThe resulting slurry was stirred at 40° C. for 1 hour
7. temperaturecooled to room temperature
8. filtrationThe resulting white solid was filtered
9. washwashed with water (2×300 ml)
10. customair-dried

ORD record

ord-37e1adc7acfc47afbb21abe9e64153f1

Source dataset

uspto-grants-1999_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05863936