Reaction conditions investigation of the Sn2/lactamization process.

Entry	Base (1 eq.)	M	T (°C)	t	Yielda/notes
1	—	0.20	rt	96 h	Sm in complex mixture
2	—	0.20	50	24 h	30%
3	NaHCO3	0.20	50	48 h	No react.
4	K2CO3	0.20	50	24 h	45%
5	DIPEA	0.20	50	24 h	80%
6	DIPEA	0.10	50	24 h	57%
7	DIPEA	0.20	rt	24 h	Sm and acyclic intermediate
8	DIPEA	Solvent free	rt	24 h	Sm and acyclic intermediate
9	DIPEA	Solvent free	50	24 h	Complex mixture of products

^aIsolated yields by chromatography.