반응 #12019

반응 방정식

water

ethyl acetate

(4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

intermediate b

(4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

triethylamine

→

product

수율 74.4%

(4R,9aR)-4-Methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2,6-dicarboxylic acid 2-tert-butyl ester 6-methyl ester

수율 74.4%

용매

brine

methanol

반응 조건

후처리

1. 1
   추출was extracted with further portions of ethyl acetate
2. 2
   기타The combined organic layers were separated
3. 3
   건조dried over magnesium sulfate
4. 4
   여과filtered
5. 5
   기타The residue was purified by chromatography on silica gel (0.032–0.063 mm)

실험 절차

To a solution of 6.0 g (16.3 mmol) (4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (Example 5, intermediate b) in 60 ml methanol were added 0.57 g (0.8 mmol) and 3.4 ml (2.5 g, 24.4 mmol) triethylamine and the reaction mixture was stirred at 80 deg C. for 24 h under a carbon monoxide atmosphere of 40 bar. The suspension was cooled to room temperature, poured into a mixture of water, ethyl acetate and brine and was extracted with further portions of ethyl acetate. The combined organic layers were separated, dried over magnesium sulfate and filtered. The residue was purified by chromatography on silica gel (0.032–0.063 mm) to afford the product as a light yellow foam (74.4%).

출처