Ethanol → Methyl(2-phenylethyl)amine hydrochloride

Phenylacetaldehyde (24.0 g, 0.20 mol), a 33% solution of methylamine in ethanol (42.35 g, 0.41 mol) and methylamine hydrochloride (10.13 g, 14.8 mmol) were dissolved in methanol (200 ml). Sodium cyanoborohydride (3.77 g, 60 mmol) was introduced and the reaction mixture was stirred at room temperature for 18 h. The reaction mixture was evaporated in vacuo to ca. 50 ml, concentrated hydrochloric acid (40 ml) was added and once the exotherm had subsided the reaction mixture was stirred for 2 h. Water (200 ml) was introduced followed by potassium hydroxide (27 g, 0.48 mol) and the cooled solution was extracted with dichloromethane (7×100 ml). The combined dichloromethane extracts were extracted with 2N hydrochloric acid solution (200 ml) and 0.2N hydrochloric acid solution (200 ml). The combined acidic extracts were washed with dichloromethane (2×50 ml) and the aqueous phase was basified with 4N sodium hydroxide solution before being extracted with dichloromethane (2×100 ml). The combined extracts were dried (MgSO4) and evaporated to a residue (9.2 g) which was dissolved in toluene (200 ml) with methanol (5 ml) present. Chlorotrimethylsilane (8.63 ml) dissolved in toluene (300 ml) was added and the hydrochloride salt of N-methyl-2-phenylethylamine precipitated. After cooling the suspension, the solid was collected by filtration and dried in vacuo; 1H NMR (DMSO-d6)γ2.54 (3H, s, --CH3), 2.92-3.07 (4H, m, --CH2CH2 --), 7.20-7.40 (5H, m, Ar-H).

1. customThe reaction mixture was evaporated in vacuo to ca. 50 ml, concentrated hydrochloric acid (40 ml)
2. additionwas added
3. stirringwas stirred for 2 h
4. additionWater (200 ml) was introduced
5. extractionthe cooled solution was extracted with dichloromethane (7×100 ml)
6. extractionThe combined dichloromethane extracts were extracted with 2N hydrochloric acid solution (200 ml) and 0.2N hydrochloric acid solution (200 ml)
7. washThe combined acidic extracts were washed with dichloromethane (2×50 ml)
8. extractionbefore being extracted with dichloromethane (2×100 ml)
9. dry with materialThe combined extracts were dried (MgSO4)
10. customevaporated to a residue (9.2 g) which
11. dissolutionwas dissolved in toluene (200 ml) with methanol (5 ml) present
12. dissolutionChlorotrimethylsilane (8.63 ml) dissolved in toluene (300 ml)
13. additionwas added
14. customthe hydrochloride salt of N-methyl-2-phenylethylamine precipitated
15. temperatureAfter cooling the suspension
16. filtrationthe solid was collected by filtration
17. customdried in vacuo

ORD-Eintrag

ord-81f31171dddd4f3584ab181c217b0b28

Quelldatensatz

uspto-grants-1995_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05430027