反应详情

A suspension of 3.1 g of finely ground 1-(4-bromopyrrol-2-ylmethylene)pyrrolidinium bromide (0.01 mole) in 30 ml of dry tetrahydrofuran (THF) is stirred at room temperature under N2 while 30 ml of 1M borane.- THF complex is added dropwise over 10 minutes with stirring, and the whole is stirred for a further 21/2 hours while being chilled in an ice bath. Then 10 ml of 1N NaOH is added dropwise and hydrogen is evolved. The reaction mixture is acidified and extracted with ether; the combined extracts are washed with brine and dried over potassium carbonate. Evaporation in vacuo gives as a light red viscous oil 4-bromo-2-(1-pyrrolidinemethyl)-pyrrole-borane complex. IR (neat): 3500, 3050, 2400, 2310 cm-1.

1. addition- THF complex is added dropwise over 10 minutes
2. stirringthe whole is stirred for a further 21/2 hours
3. temperaturewhile being chilled in an ice bath
4. extractionextracted with ether
5. washthe combined extracts are washed with brine
6. dry with materialdried over potassium carbonate
7. customEvaporation in vacuo
8. customgives as a light red viscous oil 4-bromo-2-(1-pyrrolidinemethyl)-pyrrole-borane complex