TLR7 agonist 27 (compound 24) is a potent TLR7 agonist with an EC 50 of 238.1 nM. TLR7 agonist 27 shows weak agonistic activity against NOD2 (nucleotide-binding oligomerization domain 2) ( EC 50 of 6.2 μM). TLR7 agonist 27 is a potent immunostimulant, and can be used as a vaccine adjuvant and/or immunotherapeutic.