calculated for C12H9O2N2S [M+H]+ 245.03792; found 245.03760.
1
5.2.6.16 N-(benzo[d]oxazol-2-yl)-5-chlorothiophene-2-carboxamide (16). White solid, 49% yield. H NMR (600 MHz, DMSO-d6): δ
7.74 (brs, 1H), 7.59 (d, J = 7.2 Hz, 1H), 7.51 (brs, 1H), 7.33 (dt, J = 7.2, 1.2 Hz, 1H), 7.29 (dt, J = 7.2, 1.2 Hz, 1H), 7.24 (brs, 1H). 13
C
NMR (150 MHz, DMSO-d6): δ 131.2, 128.5, 125.0, 124.0, 110.3. HRMS-ESI (m/z): calculated for C12H8ClO2N2S [M+H]+ 278.99895,
found 278.99908.
1
5.2.6.17 N-(benzo[d]oxazol-2-yl)benzamide (17). White solid, 75% yield. H NMR (600 MHz, DMSO-d6): δ 12.06 (brs, 1H), 8.05
(overlap, 2H), 7.63 (brt, J = 7.2 Hz, 2H), 7.60 (overlap, 1H), 7.54 (brt, J = 7.2 Hz, 2H), 7.33 (dt, J = 7.2, 1.2 Hz, 1H), 7.30 (dt, J = 7.2,
1.2 Hz, 1H). 13C NMR (150 MHz, DMSO-d6): δ 165.0, 155.5, 147.8, 140.6, 132.6, 128.5, 124.7, 123.9, 118.3, 110.2. HRMS-ESI (m/z):
calculated for C14H11O2N2 [M+H]+ 239.08150; found 239.08170.
1
5.2.6.18 4-methyl-N-(4-(pyridin-2-ylmethoxy)benzo[d]oxazol-2-yl)-1,2,3-thiadiazole-5-carboxamide (25). Yellow solid, 47% yield. H
NMR (400 MHz, DMSO-d6): δ 10.66 (s, 1H), 8.45 (ddd, J = 4.8, 1.6, 0.8 Hz, 1H), 7.81 (dt, J = 7.6, 2.0 Hz, 1H), 7.44 (brd, J = 7.6 Hz,
1H), 7.29 (ddd, J = 6.0, 4.8, 0.8 Hz, 1H), 7.14 (dd, J = 8.4, 8.4 Hz, 1H), 7.13 (s, 1H), 6.79 (ddd, J = 8.4, 8.4, 6.0 Hz, 1H), 5.55 (s, 2H),
2.80 (s, 3H). 13C NMR (100 MHz, DMSO-d6): δ 163.7, 159.3, 155.8, 154.8, 149.1, 148.4, 145.8, 144.3, 137.1, 124.6, 122.7, 121.4,
117.4, 112.8, 105.7, 102.0, 48.9, 13.4. HRMS-ESI (m/z): calculated for C17H14O3N5S [M+H]+ 368.08119, found 368.08169.
5.2.6.19 4-methyl-N-(4-(pyrimidin-2-yloxy)benzo[d]oxazol-2-yl)-1,2,3-thiadiazole-5-carboxamide (26). White solid, 29% yield. 1H
NMR (400 MHz, DMSO-d6): δ 8.63 (d, J = 4.8 Hz, 2H), 7.59 (d, J = 8.0 Hz, 1H), 7.38 (t, J = 8.0 Hz, 1H), 7.28 (t, J = 4.8 Hz, 1H), 7.24
(d, J = 8.0, 0.8 Hz, 1H), 2.83 (s, 3H). 13C NMR (100 MHz, DMSO-d6): δ 164.3, 160.3, 160.1, 158.4, 158.0, 129.7, 124.7, 118.4, 117.2,
108.0, 105.8, 13.4. HRMS-ESI (m/z): calculated for C15H11O3N6S [M+H]+ 355.06079, found 355.06039.
1
5.2.6.20 4-methyl-N-(naphtho[1,2-d]oxazol-2-yl)-1,2,3-thiadiazole-5-carboxamide (27). Black solid, 58% yield. H NMR (400 MHz,
DMSO-d6) δ 8.58 (s, 1H), 8.09 (d, J = 8.0 Hz, 1H), 7.93 (d, J = 8.8 Hz, 1H), 7.86 (d, J = 8.8 Hz, 1H), 7.69 (dt, J = 8.0, 1.2 Hz, 1H),
7.59 (dt, J = 80, 1.2 Hz, 1H), 2.93 (s, 3H). 13C NMR (100 MHz, DMSO-d6): δ 160.0, 130.8, 128.8, 127.2, 125.7, 125.2, 121.9, 110.7,
13.5. HRMS-ESI (m/z): calculated for C15H11O2N4S [M+H]+ 311.05972, found 311.05972.
5.2.6.21 4-methyl-N-(oxazolo[5,4-h]quinolin-2-yl)-1,2,3-thiadiazole-5-carboxamide (28). Brown solid, 35% yield. 1H NMR (400 MHz,
DMSO-d6): δ 9.02 (s, 1H), 8.55 (d, J = 8.4 Hz, 1H), 7.99 (d, J = 7.2 Hz, 2H), 7.64 (s, 1H), 2.90 (s, 3H). 13C NMR (100 MHz,
DMSO-d6): δ 160.1, 150.9, 137.1, 125.9, 124.7, 121.1, 111.6, 105.7, 13.4. HRMS-ESI (m/z): calculated for C14H10O2N5S [M+H]+
312.05497, found 312.05450.
1
5.2.6.22 4-methyl-N-(oxazolo[4,5-f]quinolin-2-yl)-1,2,3-thiadiazole-5-carboxamide (29). Yellow solid, 25% yield. H NMR (400 MHz,
DMSO-d6): δ 8.83 (s, 2H), 7.90 (d, J = 8.0 Hz, 1H), 7.77 (d, J = 6.8 Hz, 1H), 7.50 (s, 1H), 2.82 (s, 3H). 13C NMR (100 MHz,
DMSO-d6): δ 164.5, 157.8, 148.6, 145.4, 143.2, 120.5, 119.1, 113.4, 13.3. HRMS-ESI (m/z): calculated for C14H10O2N5S [M+H]+
312.05497, found 312.05453.
5.2.7 4-methyl-N-(5-(pyridin-2-yl)benzo[d]oxazol-2-yl)-1,2,3-thiadiazole-5-carboxamide (18)
A
mixture of N-(5-bromobenzo[d]oxazol-2-yl)-4-methyl-1,2,3-thiadiazole-5-carboxamide 4 (600 mg, 1.77 mmol) and
2-(butyldipentylstannyl)pyridine (843 mg, 2.12 mmol) was dissolved in 10 mL anhydrous DMF, and then CuI (50 mg, 0.27 mmol),
Pd2(dba)3 (165 mg, 0.18 mmol), and TEA (354 mg, 3.54 mmol) were added. The solution was stirred and reacted at 90°C under nitrogen
atmosphere. After 5 h, the reaction mixture was filtered through celite, and the solvent was evaporated under vacuum. The residue was
purified by prep-TLC using THF/MeOH (20/1, v/v) as an eluent. The yield of the obtained while solid product 18 (310 mg) was found
to be 52%.1H NMR (400 MHz, DMSO-d6): δ 13.46 (brs, 1H), 8.68 (brd, J = 6.0 Hz, 1H), 8.16 (d, J = 1.2 Hz, 1H), 8.03 (dd, J = 8.4, 1.6
Hz, 1H), 7.96 (d, J = 8.0 Hz, 1H), 7.90 (td, J = 8.0, 1.6 Hz, 1H), 7.70 (d, J = 8.4 Hz, 1H), 7.38 (ddd, J = 8.0, 8.0, 1.6 Hz, 1H), 2.95 (s,
3H).13C NMR (100 MHz, DMSO-d6): δ 160.0, 155.0, 149.6, 137.5, 136.4, 123.2, 122.8, 120.4, 110.8, 105.8, 13.5. HRMS-ESI (m/z):
calculated for C16H12O2N5S [M+H]+ 338.07062, found 338.07050.
5.2.8 4-methyl-N-(4-(pyridin-2-yl)benzo[d]oxazol-2-yl)-1,2,3-thiadiazole-5-carboxamide (19). The method used to synthesize this