反应详情

温度

100 °C

To a stirred solution of 3-tert-butoxycarbonylacetyl-benzoic acid methyl ester (11.1 g) and MeI (2.2 mL) in DMF (40 mL) was added portionwise at 0° C. NaH (55% dispersion in mineral oil, 1.4 g). Stirring was continued at 0° C. for 15 min and at 20° C. for 30 min. The mixture was partitioned between AcOEt and brine, the pH being set to 7 by the addition of 3N HCl. The organic layer was dried and evaporated. The residue was stirred in a mixture of CH2Cl2 (30 mL) and TFA (30 mL) for 40 min at 20° C. After the evaporation of the solvents, the solution of the residue in AcOEt was extracted with ice-cold sat. Na2CO3 solution and the aqueous extracts were immediately acidified with 3N HCl and extracted with AcOEt. The solvent of this extract was evaporated and the residue heated in a mixture of toluene (40 mL) and 3N HCl (3 mL) to 100° C. for 1 h. The cooled mixture was diluted with AcOEt, washed with sat. NaHCO3 and brine, dried and evaporated to give 3-propionyl-benzoic acid methyl ester (3.87 g) as white solid, MS (ISP) 193.2 [(M+H)+].

1. customThe mixture was partitioned between AcOEt and brine
2. additionthe pH being set to 7 by the addition of 3N HCl
3. customThe organic layer was dried
4. customevaporated
5. stirringThe residue was stirred in a mixture of CH2Cl2 (30 mL) and TFA (30 mL) for 40 min at 20° C
6. customAfter the evaporation of the solvents
7. extractionthe solution of the residue in AcOEt was extracted with ice-cold sat. Na2CO3 solution
8. extractionextracted with AcOEt
9. customThe solvent of this extract was evaporated
10. additionThe cooled mixture was diluted with AcOEt
11. washwashed with sat. NaHCO3 and brine
12. customdried
13. customevaporated