Table 2. Guanylation Optimization Using Nitroaniline 1b^a.

entry	solvent	baseb	yield of 2b (%)
1	ACN	TEA (2.0)	0
2	DMF	TEA (2.0)	0
3	DMF	KOtBu (1.0)	9
4	DMF	KOtBu (2.0)	63
5	ACN	KOtBu (2.0)	40c
6	DMFd	KOtBu (2.0)	45
7	DMFd	KOtBu (3.0)	70
8	DMF	DBU (2.0)	3
9	DMF	KHMDS (2.0)	0
10	DMF	NaH (2.0)	68

^aYields determined by GC-FID using mesitylene as an internal standard. 1.0 equiv HATU, unless stated otherwise.

^bEquivalents in parentheses.

^cComplex mixture.

^dHATU 1.5 equiv.