Table 1. Optimization of thiosalicylic S-alkylation.

Entry	Reagents a	Results
1	KOH (1 eq.), H2O	NR
2	K2CO3 (1 eq.), H2O	NR
3	KOH (1 eq.), MeOH	Decomposition
4	K2CO3 (1 eq.), MeOH	S-Propargyl propargyl thiosalicylate
5	Guanidinium carbonate (1 eq.) acetone, r.t.	S-Propargyl thiosalicylic acid, 81% yield

^aThiosalicylic acid (1 eq.), propargyl bromide (1 eq.), reflux, 12 h.