反应详情

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).

1. additionwere added
2. customReaction mixture
3. customThe above reaction mixture
4. stirringwas stirred at RT for 8 hours
5. distillationDMF was distilled off under reduced pressure
6. customto give pale brown solid, which
7. customDCU precipitated out
8. filtrationwas filtered off
9. additionWater was added
10. extractionthe aqueous layer was extracted with EtOAc
11. dry with materialOrganic layer was dried over Na2SO4
12. concentrationconcentrated under vacuum
13. customCrude compound was purified through precipitation