反应详情

A solution of 120 ml of carbon disulfide and 60.6 g of dicyclohexycarbodiimide in 300 ml of tetrahydrofuran is cooled to -8° with an ice/salt mixture. Thereupon, 39.9 g of aminoacetaldehyde diethyl acetal are added dropwise while stirring so that the temperature of the reaction mixture does not exceed -5° (approximately 1 hour). The mixture is then warmed slowly to room temperature while stirring (approximately 2 hours) and left to stand overnight. The resulting precipitate (dicyclohexylthiourea) is then removed by filtration and washed thoroughly with n-hexane. The filtrate is concentrated in a vacuum and the separated dicyclohexylthiourea is again removed by filtration and washed with n-hexane. This procedure is repeated until dicyclohexylthiourea no longer separates upon concentration. Finally, the filtrate is freed completely from solvents. The residue is distilled at 11 Torr (bath temperature 130°-134°), whereby there is obtained 2,2-diethoxyethyl isothiocyanate in the form of a colorless oil; b.p. 100°/11 Torr.

1. customdoes not exceed -5°
2. custom(approximately 1 hour)
3. stirringwhile stirring (approximately 2 hours)
4. waitleft
5. customThe resulting precipitate (dicyclohexylthiourea) is then removed by filtration
6. washwashed thoroughly with n-hexane
7. concentrationThe filtrate is concentrated in a vacuum
8. customthe separated dicyclohexylthiourea is again removed by filtration
9. washwashed with n-hexane
10. concentrationno longer separates upon concentration
11. distillationThe residue is distilled at 11 Torr (bath temperature 130°-134°)