Chloroacetaldehyde → Ethyl 2-(2,2-diethoxyethyl)-1-methyl-pyrrole-3-carboxylate

To a solution of 11.8 g of the compound obtained in Step B (50.8 mmol) in 76 mL of water there are added, dropwise at 0° C., 6.6 ml of aqueous 40% methylamine solution (76.2 mmol). The reaction mixture is stirred and gently reheated to ambient temperature over 5 hours. After returning to 0° C., 8.8 mL of aqueous 40% methylamine solution (102 mmol) and then 16.6 mL of aqueous 50% chloroacetaldehyde solution (127 mmol) are each added dropwise at a temperature of less than 10° C. The reaction mixture is stirred at ambient temperature for 16 hours and then diluted with ethyl acetate. The organic phase is washed with brine, dried over MgSO4 and concentrated to dryness. The crude product thereby obtained is purified by chromatography over silica gel using petroleum ether and ethyl acetate as eluants. The title product is obtained in the form of an oil.

1. customAfter returning to 0° C.
2. additioneach added dropwise at a temperature of less than 10° C
3. stirringThe reaction mixture is stirred at ambient temperature for 16 hours
4. washThe organic phase is washed with brine
5. dry with materialdried over MgSO4
6. concentrationconcentrated to dryness
7. customThe crude product thereby obtained
8. customis purified by chromatography over silica gel

ORD record

ord-76e866d5e6cb427d93da65ae2206a7aa

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09108983B2