Carbon Disulfide → 3-Anilino-5-phenyl-2-sulfanylidene-1,3-oxazolidin-4-one

Temperature

-30 °C

A stirred solution of potassium tert.-butoxide (11.22 g, 0.1 mole) in tetrahydrofuran (100 ml), held at 0° C. to -5° C., was treated portionwise with a solution of methyl mandelate (16.62 g, 0.1 mole) in tetrahydrofuran (70 ml), providing an orange-red solution. After 4 minutes carbon disulfide (6.04 ml, 0.1 mole) was added. After 5 minutes at 0° C. to -5° C., the orange solution was cooled to -30° C. and treated with ethyl chloroformate (9.5 ml, 0.1 mole). After 2 minutes the solution was warmed to -10° C. After 5 minutes at -10° C., the solution was cooled to -30° C. and treated with 97% phenylhydrazine (10.1 ml, 0.1 mole). The yellow solution was warmed to 25° C., and after 10 minutes the mixture was evaporated under reduced pressure to a turbid oil. The oil was mixed with water and 1-chlorobutane, the layers were separated, and the organic solution was washed with 1N HCl, water (twice), and saturated sodium bicarbonate solution. The dried (magnesium sulfate) solution was evaporated under reduced pressure to a yellow-orange oil, and the oil was dissolved in chloroform. A silica-gel filtration of the chloroform solution followed by evaporation of the filtrate under reduced pressure provided a green oil which began to solidify. Further purification was accomplished by crystallization from 1-chlorobutane. This procedure provided the product as 9.9 g (35% of theoretical) of a white solid, m.p. 140°-141° C. The infrared spectrum (Nujol mull) showed the characteristic absorption at 3295 cm-1 (N-H) and 1760 cm-1 (imide C=O).

1. customheld at 0° C. to -5° C.
2. customproviding an orange-red solution
3. temperatureAfter 2 minutes the solution was warmed to -10° C
4. waitAfter 5 minutes at -10° C.
5. temperaturethe solution was cooled to -30° C.
6. temperatureThe yellow solution was warmed to 25° C.
7. customafter 10 minutes the mixture was evaporated under reduced pressure to a turbid oil
8. additionThe oil was mixed with water and 1-chlorobutane
9. customthe layers were separated
10. washthe organic solution was washed with 1N HCl, water (twice), and saturated sodium bicarbonate solution
11. dry with materialThe dried (magnesium sulfate) solution
12. customwas evaporated under reduced pressure to a yellow-orange oil
13. dissolutionthe oil was dissolved in chloroform
14. filtrationA silica-gel filtration of the chloroform solution
15. customfollowed by evaporation of the filtrate under reduced pressure
16. customprovided a green oil which
17. customFurther purification
18. customwas accomplished by crystallization from 1-chlorobutane
19. customThis procedure provided the product as 9.9 g (35% of theoretical) of a white solid, m.p. 140°-141° C
20. customthe characteristic absorption at 3295 cm-1 (N-H) and 1760 cm-1 (imide C=O)

ORD record

ord-365e27a52ae845b5b257bad4b3def68f

Source dataset

uspto-grants-1993_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05223523