反应详情

温度

-100 °C

A solution of 3-(4-bromophenyl)-5-methyl-1,2,4-oxadiazole (1.0 g) in dry THF (8 ml) containing triisopropylborate (3.5 ml, 2.82 g) was cooled to -100° C. under nitrogen, and treated cautiously with tert-butyllithium (8.82 ml, 1.7M solution). The temperature was maintained between -90° C. and -105° C. during addition. The mixture was stirred at -100° C. for 20 mins after complete addition, and then allowed to warm to -30° C. The mixture was treated slowly with water (5 ml) and allowed to warm to room temperature, 2N sodium hydroxide (50 ml) was added and the basic aqueous layer washed with dichloromethane (2×50 ml). The aqueous layer was acidified with 2N hydrochloric acid (60 ml) and extracted with dichloromethane (4×50 ml, containing 20% methanol). The combined, dried extracts were concentrated in vacuo to give the title compound as a pale yellow solid (500 mg). m.p . 266°-268° C.

1. temperatureThe temperature was maintained between -90° C. and -105° C. during addition
2. additionafter complete addition
3. temperatureto warm to -30° C
4. temperatureto warm to room temperature
5. washthe basic aqueous layer washed with dichloromethane (2×50 ml)
6. extractionextracted with dichloromethane (4×50 ml, containing 20% methanol)
7. customdried extracts
8. concentrationwere concentrated in vacuo