Table 1.
Yield, purity, and characteristic impurities of the sulfonamide derivatives with amino acids of various polarities obtained from HPLC-ESI-DAD/QTOF/MS analysis of crude products.
| (a)-the products with hydrophobic amino acids | ||||
| Product (Mr) | Parameter | Na2CO3 | NaHCO3 | TEA |
| 2 Ala | yield of crude product (%) | 99 | 73 | 48 |
| (425.11 g/mol) | RP-HPLC-UV purity (%) | 92.55 | 93.34 | 92.18 |
| MS [M + H]+ found | 426.1196 (7.25 min) | 426.1213 (7.29 min) | 426.1210 (7.27 min) | |
| disubst. AA + OH (%) | x | x | 1.19 | |
| 3 Phe | yield of crude product (%) | 94 | 94 | 12 |
| (577.17g/mol) | RP-HPLC-UV purity (%) | 96.81 | 97.19 | 20.43 |
| MS [M + H]+ found | 578.1829 (4.38 min) | 578.1831 (4.39 min) | 578.1862 (4.36 min) | |
| 4 Tyr | yield of crude product (%) | 87 | 77 | 1.7 |
| (609.16 g/mol) | RP-HPLC-UV purity (%) | 32.72 | 27.47 | 10.57 |
| MS [M + H]+ found | 610.1727 (7.04 min) | 610.1721 (7.04 min) | 610.1766 (7.03 min) | |
| disubst. AA + OH (%) | 32.23 | 1.06 | x | |
| disubst. OH + OH (%) | 2.7 | x | 1.22 | |
| unreacted initial compounds (%) | x | 23.34 (182.0812) | 15.46 (182.0813) | |
| 5 Trp | yield of crude product (%) | 94 | 96 | 70 |
| (655.19 g/mol) | RP-HPLC-UV purity (%) | 93.12 | 87.44 | 77.82 |
| MS [M + H]+ found | 656.2051 (5.5 min) | 656.2046 (5.51 min) | 656.2050 (5.51 min) | |
| disubst. AA + OH (%) | x | 1.78 | x | |
| disubst. OH + OH (%) | x | 0.79 | x | |
| unreacted initial compounds (%) | 1.63 (205.0793) | 8.94 (205.0975) | x | |
| (b)-the products with polar uncharged amino acids | ||||
| Product (Mr) | Parameter | Na2CO3 | NaHCO3 | TEA |
| 6 Asn | yield of crude product (%) | 97 | 71 | 9.0 |
| (511.12 g/mol) | RP-HPLC-UV purity (%) | 49.66 | 88.47 | 16.31 |
| MS [M + H]+ found | 512.1320 (9.63 min) | 512.1320 (9.63 min) | 512.1340 (9.65 min) | |
| disubst. AA + OH (%) | 0.42 | 1.33 | 23.45 | |
| monosubst. AA (%) | x | x | 26.29 | |
| disubst. OH + OH (%) | 1.30 | x | 2.20 | |
| 7 Gln | yield of crude product (%) | 78 | 68 | 18 |
| (539.15 g/mol) | RP-HPLC-UV purity (%) | 21.58 | 58.04 | 55.23 |
| MS [M + H]+ found | 540.1635 (9 min) | 540.1634 (9.01 min) | 540.1650 (9.03 min) | |
| disubst. AA + OH (%) | 9.42 | 3.41 | 2.64 | |
| monosubst. AA (%) | 4.91 | 19.76 | 3.42 | |
| disubst. OH + OH (%) | 1.17 | x | x | |
| 8 Ser | yield of crude product (%) | 73 | 82 | 41 |
| (457.42 g/mol) | RP-HPLC-UV purity (%) | 87.09 | 94.86 | 4.08 |
| MS [M + H]+ found | 458.1095 (9.13 min) | 458.1095 (9.13 min) | 458.1092 (9.13 min) | |
| disubst. AA + OH (%) | 3.71 | 2.23 | 50.33 | |
| monosubst. AA (%) | x | x | 7.91 | |
| disubst. OH + OH (%) | x | x | 7.27 | |
| 9 Thr | yield of crude product (%) | 93 | 92 | 14 |
| (485.37 g/mol) | RP-HPLC-UV purity (%) | 94.42 | 96.56 | 20.93 |
| MS [M + H]+ found | 486.1411 (7.7 min) | 486.1414 (7.71 min) | 486.1415 (7.73 min) | |
| disubst. AA + OH (%) | 1.50 | 1.43 | 22.17 | |
| disubst. OH + OH (%) | x | x | 4.25 | |
| (c)-the products with acidic (negatively charged) amino acids | ||||
| Product (Mr) | Parameter | Na2CO3 | NaHCO3 | TEA |
|
10 Asp (513.09 g/mol) |
yield of crude product (%) | 90 | 46 | 16 |
| RP-HPLC-UV purity (%) | 93.07 | 17.57 | 37.68 | |
| MS [M + H]+ found | 514.1003 (10.71 min) | 514.1000 (10.74 min) | 514.1023 (10.75 min) | |
| disubst. AA + OH (%) | 5.37 | 21.96 | 6.92 | |
| monosubst. AA (%) | x | 50.99 | x | |
| disubst. OH + OH (%) | 0.32 | 1.36 | 9.99 | |
|
11 Glu (541.12 g/mol) |
yield of crude product (%) | 75 | 69 | 38 |
| RP-HPLC-UV purity (%) | 89.53 | 16.68 | 58.00 | |
| MS [M + H]+ found | 542.1313 (10.76 min) | 542.1310 (10.77 min) | 542.1340 (10.77 min) | |
| disubst. AA + OH (%) | 3.70 | 19.26 | 10.07 | |
| monosubst. AA (%) | x | 50.04 | x | |
| disubst. OH + OH (%) | x | 1.84 | 3.40 | |
Main impurities, namely precursor 1 disubstituted with AA + OH, OH + OH, and monosubstituted with AA, as well as unreacted initial compounds were monitored for each product and their presence is indicated in these tables (1a–c).