计划使用5-
甲基水杨醛制备
5-溴甲基水杨醛，找到一篇文献
Regioselective Synthesis of Bromo-Substituted 3-Arylcoumarins
5-Bromomethylsalicylaldehyde (6)
To a soln of 5-methylsalicylaldehyde (1) (2.0 g, 14.69 mmol) in
CCl4 (23.0 mL), under reflux and with tungsten light irradiation
(300 W, Philips Reflector R125 35°), was added Br2 (3.29 g, 20.57
mmol) over a period of 3 h. The soln was stirred at r.t. for a further
15 h and the resulting precipitate was filtered and washed with CCl4
to give aldehyde 6.
然后照着做一直做不出来，室温搅拌15h的时候不用钨灯照射无固体产生，用钨灯照射固体产物很少氢谱也不对，试了很多次了。
有做相关的大神么，求教下相关技巧。
上氯甲基倒是很容易
