Synthesis of 6-alkynyl-2-aminothieno[3,2-d]pyrimidin4(3H)-ones 2b–2h.

Compound	R1	R2	Yield (%)
2b	tBu	4-Me–Ph–	60
2c	iPr	4-Me–Ph–	23
2d	tBu	HO(CH2)2–	47
2e	tBu	Cyclopropyl–	23
2f	tBu	H–	57a
2g	tBu	N-Methylpiperazinyl–CH2–	35
2h	iPr	Ph–	85

^aTwo steps.