Triethylamine → 2-(tert-butyl) 4-ethyl 3-methyl-5-(3-((methylsulfonyl)oxy)propyl)-1H-pyrrole-2,4-dicarboxylate

Temperature

-10 °C

5-(3-Hydroxy-propyl)-3-methyl-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester 1f (9.20 g, 30 mmol) was dissolved in 150 ml of dichloromethane under stirring, and added with triethylamine (7.0 ml, 50 mmol) to the solution while maintaining the temperature at about −10° C. in an ice-salt bath under an argon atmosphere. Upon completion of the addition, the mixture was added slowly with methanesulfonyl chloride (3.5 ml, 45 mmol). After stirring to mix well, the reaction system was allowed to warm up to room temperature and stirred for 4 hours. After thin lay chromatography showed the disappearance of starting materials, the reaction mixture was quenched with ice. The reaction mixture was washed successively with dilute hydrochloric acid (0.5 mol/L, 80 ml×2) to remove triethylamine, saturated sodium carbonate solution (80 ml×2) to remove excess hydrochloric acid and saturated brine (80 ml), and concentrated under reduced pressure to obtain the title compound 5-(3-methanesulfonyloxy-propyl)-3-methyl-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester 1 g (11.4 g, yield 99%) as a brown oil.

1. additionUpon completion of the addition
2. stirringAfter stirring
3. additionto mix well
4. temperatureto warm up to room temperature
5. stirringstirred for 4 hours
6. customthe reaction mixture was quenched with ice
7. washThe reaction mixture was washed successively with dilute hydrochloric acid (0.5 mol/L, 80 ml×2)
8. customto remove triethylamine, saturated sodium carbonate solution (80 ml×2)
9. customto remove excess hydrochloric acid and saturated brine (80 ml)
10. concentrationconcentrated under reduced pressure

ORD record

ord-f2eb12cf204e45d19f2440e33611f315

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08329682B2