Hydrochloric Acid → 1-N-[2-(diethylamino)ethyl]-4-nitrobenzene-1,2-diamine

Temperature

65 °C

N′-(2,4-Dinitro-phenyl)-N,N-diethyl-ethane-1,2-diamine 3a (0.63 g, 2.322 mmol) was dissolved in anhydrous EtOH (9 mL) in a 2 neck 100 mL argon purged flask. The reaction vessel was fitted with a condenser and dropping funnel and heated in an oil bath to 65° C. H2O (7.5 mL), EtOH (15 mL) and aqueous (NH4)2S (50 wt %, 1.064 g, 7.807 mmol) were charged to the dropping funnel and added to the hot reaction mixture dropwise over 30 minutes. The reaction was heated at 65-70° C. for 2 hours then cooled to room temperature overnight. Mixture was acidified by the addition of aqueous 1M HCl to adjust pH to 0-1. The reaction mixture was filtered to remove any insoluble material and the filtrate was concentrated under reduced pressure to remove EtOH. The resulting aqueous solution was basified by the addition of aqueous 2M ammonium hydroxide solution to adjust pH to 9-10. The aqueous solution was diluted with dichloromethane and transferred to a separatory funnel and the organic layer collected. The aqueous layer was further extracted with dichloromethane and the combined organic layers were washed with H2O, brine, and dried over magnesium sulphate, filtered and concentrated to afford a dark red oil. The product was purified using silica gel dry column chromatography with a solvent system of (5% 2M NH3 in methanol/95% dichloromethane) to afford an orange oil/solid 4a N1-(2-Diethylamino-ethyl)-4-nitro-benzene-1,2-diamine. Yield: 0.476 grams (84.5%). 1H NMR (DMSO) δ 0.96 (t, 6H, J=7.1), 2.52 (m, 4H), 2.62 (t, 2H, J=6.8), 3.24 (m, 2H), 5.09 (br s, 2H), 5.82 (br s, 1H), 6.49 (d, 1H, J=8.9), 7.42 (d, 1H, J=2.6), 7.53 (dd, 1H, J=8.9, 2.6); MS (ESI): 253 (MH+, 100%)

1. customThe reaction vessel was fitted with a condenser
2. additionadded to the hot reaction mixture dropwise over 30 minutes
3. temperatureThe reaction was heated at 65-70° C. for 2 hours
4. temperaturethen cooled to room temperature overnight
5. filtrationThe reaction mixture was filtered
6. customto remove any insoluble material
7. concentrationthe filtrate was concentrated under reduced pressure
8. customto remove EtOH
9. additionThe resulting aqueous solution was basified by the addition of aqueous 2M ammonium hydroxide solution
10. additionThe aqueous solution was diluted with dichloromethane
11. customtransferred to a separatory funnel
12. customthe organic layer collected
13. extractionThe aqueous layer was further extracted with dichloromethane
14. washthe combined organic layers were washed with H2O, brine
15. dry with materialdried over magnesium sulphate
16. filtrationfiltered
17. concentrationconcentrated
18. customto afford a dark red oil
19. customThe product was purified
20. dry with materialdry column chromatography with a solvent system of (5% 2M NH3 in methanol/95% dichloromethane)

ORD record

ord-ccbb13ea3bff44f59c50d39f2bff2e14

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07919510B2