反应详情

A stirred solution of 0.84 gram (2.1 mmole) of 3-(2-t-butyl-4-chlorobenzoxazol-7-yl)-1-methyl-6-trifluoromethyl-2,4-(1H,3H)pyrimidinedione (prepared as described in Example 2) in 20 mL of acetic acid had 0.16 gram (1.0 mmole) of N,N-dichlorourethane added via syringe. Upon completion of the addition the clear reaction mixture was stirred for 15 minutes, then one drop of concentrated hydrochloric acid was added, and the reaction mixture was stirred at ambient temperature for 72 hours. After this time the reaction mixture was poured into 100 mL of water, and 10 grams of sodium carbonate were added. The mixture was extracted with three 50 mL portions of methylene chloride. The organic extracts were combined and washed with one 50 mL portion of an aqueous 5% sodium carbonate solution. The organic layer was dried with sodium sulfate and filtered. The filtrate was concentrate under reduced pressure, yielding a pale yellow oil which was subjected to column chromatography on silica gel. Elution was accomplished with 9:1 heptane:ethyl acetate, followed by 2:1 heptane:ethyl acetate. The product-containing fractions were combined and concentrated under reduced pressure, yielding 0.57 gram of 3-(2-t-butyl-4-chlorobenzoxazol-7-yl)-1-methyl-5-chloro-6-trifluoromethyl-2,4-(1H,3H)pyrimidinedione, m.p. 83°-86° C. The NMR spectrum was consistent with the proposed structure.

1. additionadded via syringe
2. additionUpon completion of the addition the clear reaction mixture
3. stirringthe reaction mixture was stirred at ambient temperature for 72 hours
4. additionwere added
5. extractionThe mixture was extracted with three 50 mL portions of methylene chloride
6. washwashed with one 50 mL portion of an aqueous 5% sodium carbonate solution
7. dry with materialThe organic layer was dried with sodium sulfate
8. filtrationfiltered
9. concentrationThe filtrate was concentrate under reduced pressure
10. customyielding a pale yellow oil which
11. washElution
12. concentrationconcentrated under reduced pressure