Tetrahydrofuran → Methyl 4-(1-trans-tridecenyl)pyrrole-2-carboxylate

To a tetrahydrofuran suspension (200 ml) of 32 g (62.7 mmol) of dodecyltriphenylphosphonium bromide was added dropwise 40 ml of a ca. 15% solution of n-butyllithium in hexane under ice-cooling. After stirring the reaction mixture for 30 minutes, the temperature was dropped to -78° C. A tetrahydrofuran solution (100 ml) of 4.8 g (31.4 mmol) of methyl 4-formylpyrrole-2-carboxylate was then added dropwise. After stirring for 1 hour, 190 of ethanol was further added thereto dropwise. The reaction mixture was stirred for 1.5 hour at -78° C., and for another 12 hours while the temperature was gradually raised to room temperature. The resulting mixture was diluted with water, extracted with ethyl acetate, washed with aqueous saturated sodium chloride solution and dried over anhydrous magnesium sulfate. After removing he solvent under reduced pressure, the residue was purified by subjecting it to column chromatography (eluent: ethyl acetate/hexane=1/10) and by recrystallizing twice from hexane to obtain 1.30 g (14 % yield) of methyl 4-(1-trans-tridecenyl)pyrrole-2-carboxylate, m.p. 65°-67° C.

1. temperaturecooling
2. additionthe temperature was dropped to -78° C
3. stirringAfter stirring for 1 hour
4. stirringThe reaction mixture was stirred for 1.5 hour at -78° C.
5. extractionextracted with ethyl acetate
6. washwashed with aqueous saturated sodium chloride solution
7. dry with materialdried over anhydrous magnesium sulfate
8. customAfter removing he solvent under reduced pressure
9. customthe residue was purified
10. customby recrystallizing twice from hexane

ORD record

ord-ecb63c61172b43d8b9cf15955b0ff9d3

Source dataset

uspto-grants-1995_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

USRE035096