反应详情

温度

4 °C

Octadecyl amine hydrochloride was converted to the amine by mixing an ether solution of the amine hydrochloride with 1 M NaOH, separating and evaporating the ether layer, dissolving the amine in CHCl3, filtering through Whatman 541 filter paper and evaporating the CHCl3. Octadecyl amine (5.9252 g, 22.0 mmol) in 150 ml ethanol was reacted with an excess (4.32 g, 24.1 mmol) of 3-methoxybenzyl isothiocyanate at 40° C. under N2 with stirring. Excess isothiocyanate was used because co-crystallization of octadecyl amine is difficult to prevent when an excess of amine is present. After 2 h the solution was cooled to 4° C., centrifuged at 10,000 rpm for 20 min and the precipitated crystals were washed with ethanol (20 ml). The combined supernatant and wash was evaporated to 20 ml total volume and then cooled to −10° C. to filter off a second batch of crystals. The supernatant was dried and 94.3% of reagents weight was recovered, 74.9%, or 7.40 g as 1-(3-methoxybenzyl)-3-(octadecyl) thiourea of about 76% purity based on the sulfur analysis. The octadecyl amine was difficult to separate from the thiourea by crystallization. Calculated elemental analysis of 1-(3-methoxybenzyl)-3-octadecyl thiourea: C, 72.27; H, 10.78; N, 6.24; S, 7.15. Found: C, 71.96; H, 11.00; N, 5.95; S, 5.46. A recrystallization from acetone/chloroform gave crystals with the composition: C, 72.37; H, 10.98; N, 6.13; S, 6.92.

1. customseparating
2. customevaporating the ether layer
3. dissolutiondissolving the amine in CHCl3
4. filtrationfiltering through Whatman 541
5. filtrationfilter paper
6. customevaporating the CHCl3
7. washthe precipitated crystals were washed with ethanol (20 ml)
8. washThe combined supernatant and wash
9. customwas evaporated to 20 ml total volume
10. temperaturecooled to −10° C.
11. filtrationto filter off a second batch of crystals
12. customThe supernatant was dried
13. custom94.3% of reagents weight was recovered
14. customto separate from the thiourea by crystallization
15. customA recrystallization from acetone/chloroform
16. customgave crystals with the composition