3.3.3- trinitropropyl carbamate

Such carbamates can be further nitrated, e.g., W-pentafluorosulfanyl-3,3,3-trinitropropyl carbamate is nitrated with trifluoroacetyl nitrate [a mixture of (CF3C0)20 + 100% HN03] to produce AT-pentafluorosul-fanyl-./V-nitro-3,3,3-trinitropropyl carbamate in 43% yield 159). 

Trinitropropyl carbamate 122 was prepared via the corresponding chloro-formate 121 using triphosgene [65]. 

Typical procedure. 3,3,3-Trinitropropyl carbamate 122 [65] To a stirred mixture of triphosgene (1.8 g, 6 mmol) and 3,3,3-trinitropropanol (3.1 g, 16 mmol) in di-chloromethane (10 mL) at 0 °C, a solution of pyridine (1.5 mL, 19 mmol) in dichloromethane (5 mL) was added dropwise. After 24 h at room temperature, the reaction mixture was cooled to —10 °C, whereupon concentrated ammonium hydroxide (30%, 2 mL, 32 mmol) was added dropwise with stirring. The precipitated solid was removed by filtration and the filtrate was extracted with water and dilute hydrochloric acid. The volatiles were removed to give 2.75 g of product, which was chromatographed on silica gel 40 (eluting first with dichloromethane and then with dichloromethane/acetone, 80 20) to yield 0.65 g of solid mp 82-84 °C. 

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