tert-Butyl carbazate → 5-(2-Chloro-6-methylpyridin-4-yl)-3-methyl-1,3,4-oxadiazol-2(3H)-one

Step-1: t-Butyl-2-(2-chloro-6-methylisonicotinoyl)hydrazinecarboxylate: To a stirred solution of 2-chloro-6-methylisonicotinic acid (4.0 g, 23.3 mmol) in DMF (40 mL) was added successively tert-butyl hydrazine carboxylate (3.0 g, 23.3 mmol), TBTU (6.0 g, 18.6 mmol) and DIPEA (12.2 mL, 69.9 mmol). After stirring for 12 hat RT, water (20 mL) was added to the reaction followed by ethyl acetate (50 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with brine (50 mL), dried (Na2SO4) and filtered. The filtrate was concentrated under vacuum to afford 3.0 g (45%) of the title compound as white solid. 1HNMR (400 MHz, CDCl3) δ 8.65 (s, D2O exchangeable, 1H), 7.48 (s, 1H), 7.42 (s, 1H), 6.77 (s, D2O exchangeable, 1H), 2.59 (s, 3H), 1.53 (s, 9H); GC-MS (m/z) 185 (M)+

1. additionwas added to the reaction
2. customThe layers were separated
3. extractionthe aqueous layer was extracted with ethyl acetate (3×50 mL)
4. washThe combined organic layers were washed with brine (50 mL)
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationThe filtrate was concentrated under vacuum

ORD 기록

ord-9f9a3496de264abfbb2a944a5de67b00

출처 데이터셋

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US09399638B2