Thionyl Chloride → Ethyl 2-methoxyimino-2-(1,2,3-thiadiazol-4-yl)acetate

Temperature

50 °C

A mixture of ethyl 2-methoxyimino-3-t-butoxycarbonylhydrazonobutyrate (a mixture of syn and anti isomers) (28.7 g.) and thionyl chloride (30 ml.) was warmed with stirring on a water bath of 50° C. for 3 minutes and then stirred for 5 minutes at ambient temperature to give black solution. To the reaction mixture was added ethyl acetate (200 ml.) and the mixture was poured into ice-water (300 ml.). The ethyl acetate layer was separated, washed in turn with water, with a saturated aqueous solution of sodium bicarbonate and with a saturated aqueous solution of sodium chloride. After drying over magnesium sulfate, the ethyl acetate solution was treated with activated charcoal and concentrated to give black oil. The oil was purified by column chromatography on silica gel using a mixture of benzene and ethyl acetate (19:1) as an eluent to give ethyl 2-methoxyimino-2-(1,2,3-thiadiazol-4-yl)acetate (anti isomer) (4 g.).

1. temperaturewas warmed
2. stirringstirred for 5 minutes at ambient temperature
3. customto give black solution
4. customThe ethyl acetate layer was separated
5. washwashed in turn with water, with a saturated aqueous solution of sodium bicarbonate and with a saturated aqueous solution of sodium chloride
6. dry with materialAfter drying over magnesium sulfate
7. additionthe ethyl acetate solution was treated with activated charcoal
8. concentrationconcentrated
9. customto give black oil
10. customThe oil was purified by column chromatography on silica gel using
11. additiona mixture of benzene and ethyl acetate (19:1) as an eluent

ORD record

ord-d23748a3a5254e629c250be1da11f574

Source dataset

uspto-grants-1982_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04350693