反应详情

The general procedure for the formation of ureas using 4-methoxyphenyl isocyanate (vide supra) was carried out on resin 33 followed directly by the general procedure for the formation of amides using iso-propyl amine, PyBoP and DIPEA (vide supra) to yield a yellow solid (77% yield by mass; 65% yield by 1H NMR with EtOAc int. std.): 1H NMR (300 MHz, 5% D2O in CD3OD, the sample was made up >16 h prior to running in order to obtain full exchange of the secondary amide proton with deuterated solvents) δ 7.89 (br s, 1H), 7.80 (br s, 2H), 7.31 (d, J=9 Hz, 2H), 6.88 (d, J=9 Hz, 2H) 4.17 (h, J=7 Hz, 1H), 3.76 (s, 3H), 1.24 (d, J=7 Hz, 6H); 13C NMR (75 MHz, 5% D2O in CD3OD) δ 170.1, 157.3, 156.0, 140.0, 136.2, 133.0, 128.9, 128.0, 123.0, 121.2, 115.2, 56.1, 43.2, 22.6; IR (microscope) 3399, 3310, 2970, 1664, 1626, 1599, 1547, 1514 cm−1; HRMS (ES, m/z) calcd for C18H22BN3O5Na (M+Na)+ 394.1550. found 394.1549.