Table 2. Screening of Acidic Conditions for Post-cyclization.

			yield (%)a
entry	acid, solvent	amount, time	6a	7a
1	TFA, MeOH	2 equiv., 18 h	10	traces
2	6 M aq. HCl	5 mL, 18 h	33	traces
3	acetyl chloride, MeOH	2 equiv., 18 h	36	5
4	2 M HCl in MeOH	5 mL, 4 h	64	6

^aIsolated yield.