Table 4.

SAR around hit series 1 c.

Compd	R1	R	TbTryS IC50 [μm]
25	H	(+/−)-CH(CH3)Ph	5.6
26	H	CH2-4-chlorophenyl	3.0
27	H	CH2-2-thiophene	3.9
28	H	CH2CH2Ph	5.6
29	H	(+/−)-CH(CH3)CH2CH3	12
30	H	CH2CH2CH3	13
31	H	CH2CH2OCH3	30
32	H	Ph	>100
33	H	cHex	>100
34	CH2Ph	CH2Ph	>100
35	CH2CH3	CH2CH3	15

[a] Conditions: 1) ethyl 2-hydrazinylacetate, Et₃N, EtOH, reflux, 61 % yield; 2) 2 m NaOH, THF/H₂O (2:1), 89 % yield; 3) RR¹NH, EDC⋅HCl, HOBt, DIPEA, DMF, 50 °C; yields: 79–80 %.