Triethylamine → (S)-Methyl 2-(3-(4-(3-(2-fluorophenyl)ureido)phenyl)isoxazole-5-carboxamido)-3-hydroxypropanoate

Participants

Reaction Steps

3-(4-(3-(2-fluorophenyl)ureido)phenyl)isoxazole-5-carboxylic acid (example 105, step 2, 1 g, 293 mmol) was dissolved in DMF (20 ml) and, to it N,N′-Dicyclohexyl carbodiimide (724 mg, 3.51 mmol) and 1-Hydroxy benzotriazole (593 mg, 4.39 mmol) were added. Reaction mixture was stirred RT for 10 minutes followed by the addition of L-serine methyl ester hydrochloride (683 mg, 4.39 mmol) dissolved in DMF (5 ml) neutralized with triethylamine (0.6 ml, 4.39 mmol). The above reaction mixture was stirred at RT for 8 hours. DMF was distilled off under reduced pressure to give pale brown solid, which was taken in THF. DCU precipitated out and was filtered off. Water was added and the aqueous layer was extracted with EtOAc. Organic layer was dried over Na2SO4 and concentrated under vacuum. Crude compound was purified through precipitation using DCM and petroleum ether to yield 500 mg (39%) of the required compound as white solid. MS: ES (−): m/z 441(M−1); ES (+): m/z 443 (M+1); 1HNMR (DMSO-d6; 300 MHz): δ 9.342 (s, 1H), 9.109 (d; 1H), 8.633 (s, 1H), 8.161 (t, 1H), 7.369 (d, 2H), 7.676 (s, 1H), 7.619 (d, 2H), 7.242 (m, 1H), 7.066 (t, 1H), 7.024 (m, 1H), 5.149 (t, 1H), 4.575 (m, 1H), 3.821 (t, 2H), 3.657 (s, 3H).

Provenance & Evidence