三溴化硼二氯溶液或者純的三溴化硼都可以，一般是兩當(dāng)量以上吧，不是很危險，就是打開時冒煙很厲害，小心操作沒有問題，在-50 度以下加入，室溫反應(yīng)很快的

這個反應(yīng)后處理很重要，生成的硼化合物需要根據(jù)其性質(zhì)想辦法除去才行

在惰性氣體氛圍和0°C下，將三溴化硼的二氯甲烷（或二氯乙烷-78度）溶液緩慢滴加到原料的二氯甲烷溶液中發(fā)生脫甲基化反應(yīng)。滴加完畢后，回復(fù)室溫攪拌幾小時。反應(yīng)完后，在冰浴下加水處理，經(jīng)萃取、干燥、過濾、濃縮就行了，原料與三溴化硼的加料摩爾比一般為3/1~1/1

這是我做過的BBr3（溶液）脫甲基的步驟
To a solution of 6-methoxyquinoline-4-carbaldehyde (3.6 g, 19.23 mmol) in dry Dichloromethane (DCM) (150 mL)  was added tribromoborane (19.27 g, 77 mmol) dropwise under nitrogen at -78oC. After addition, the reaction solution was stirred at room temperature for overnight. Then the mixture was cooled to -78oC, and then water was added dropwise to it until no gas was liberated. The reaction mixture was then extracted with CH2Cl2, then EA. The organic layer was washed with brine, dried over Na2SO4 and concentrated to obtain a crude product 6-hydroxyquinoline-4-carbaldehyde (1.8g, 9.44 mmol, 49.1 % yield).
后處理也可以這樣：反應(yīng)結(jié)束后，直接倒入冰水中，然后旋蒸除去DCM，之后用NaHCO3調(diào)堿性至9-10，析出黃色固體，抽濾，固體就是產(chǎn)物，