Dichloromethane → O-cyclohexylhydroxylamine hydrochloride

Temperature

25 °C

Hydrazine monohydrate (2.24 mL, 42.20 mmol) was added to a solution of 2-cyclohexyloxy-isoindole-1,3-dione (4.88 g, 21.10 mmol) in a mixture of methanol (12 mL) and methylene chloride (120 mL), and the mixture was stirred at 25° C. for 4 h. The resulting precipitate was filtered off in vacuo, and the filtrate was washed with 5.0 N aqueous ammonium hydroxide (60 mL). The aqueous layer was extracted with methylene chloride (2×25 mL). The combined organic layers were washed with brine, dried over magnesium sulfate and concentrated in vacuo. The residue was dissolved in a 4.0 M solution of hydrochloric acid in dioxane (12 mL) and diluted with diethyl ether (70 mL). The resulting precipitate was collected by filtration in vacuo to afford O-cyclohexyl-hydroxylamine hydrochloride (1.71 g, 45.7%) as a white solid, which was used in the next step without further purification.

1. filtrationThe resulting precipitate was filtered off in vacuo
2. washthe filtrate was washed with 5.0 N aqueous ammonium hydroxide (60 mL)
3. extractionThe aqueous layer was extracted with methylene chloride (2×25 mL)
4. washThe combined organic layers were washed with brine
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated in vacuo
7. dissolutionThe residue was dissolved in a 4.0 M solution of hydrochloric acid in dioxane (12 mL)
8. additiondiluted with diethyl ether (70 mL)
9. filtrationThe resulting precipitate was collected by filtration in vacuo

ORD record

ord-889dfa8877f14d8c898b221ebbeaa555

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07902248B2