. 2019 Apr 1;9(18):10091–10093. doi: 10.1039/c9ra01517e

The bromination of ML to M5B^a.

Entry	Bromine source	Solvent	M5B yield (%)
1	CuBr₂	CH₃OH	50
2	CuBr₂	CHCl₃	7
3	CuBr₂	EA	13
4	CuBr₂	CH₃OH/EA (1 : 1)	32
5	CuBr₂	CHCl₃/EA (1 : 1)	14
6	CuBr₂	CH₃OH/CHCl₃ (1 : 1)	80
7	CuBr₂	CH₃OH/CHCl₃ (4 : 1)	56
8	CuBr₂	CH₃OH/CHCl₃ (3 : 1)	75
9	CuBr₂	CH₃OH/CHCl₃ (1 : 3)	74
10	CuBr₂	CH₃OH/CHCl₃ (1 : 4)	66
11^b	ZnBr₂	CH₃OH/CHCl₃ (1 : 1)	0
12^b	MgBr₂	CH₃OH/CHCl₃ (1 : 1)	0
13^b	AlBr₃	CH₃OH/CHCl₃ (1 : 1)	0
14	Br₂	CH₃OH/CHCl₃ (1 : 1)	55
15	2C₄H₉NOHBr·Br₂	CH₃OH/CHCl₃ (1 : 1)	40
16	NBS + BPO	CH₃OH/CHCl₃ (1 : 1)	28
17	NBS + AIBN	CH₃OH/CHCl₃ (1 : 1)	18

Reaction condition: ML = 0.33 g, bromine source = 3 mole of ML, solvent = 30 mL, temperature = 40 °C, time = 3 h.

Time = 24 h.

The bromination of ML to M5Ba.