2,5-Dihydroxybenzoic acid → HCID 11508769, compound

A hot solution of 2,5-dihydroxybenzoic acid (gentisic acid) (0.582 g, 3.78 mmol) in absolute ethanol (1 mL) was added to a warm solution of (2S)-(4E)-N-methyl-5-(5-methoxy-3-pyridinyl)-4-penten-2-amine (1.00 g, 4.85 mmol, 86.7% E isomer by GC-FID) in absolute ethanol (1 mL), using additional ethanol (2 mL) in the transfer. The resulting mixture was concentrated via rotary evaporation, leaving 1.5 mL of ethanol in the solution. With stirring and heating to near reflux, crystallization occurred. The resulting hot mixture was treated drop-wise with ethyl acetate (5.5 mL). After cooling to room temperature, the mixture was further cooled at 5° C. for 48 h. The resulting solids were filtered, washed with ethyl acetate (2×5 mL) and dried at 50° C. to give 1.24 g (91%) of an off-white powder (98.0% E isomer by GC-FID for the free base). To remove the color from the sample, the material was recrystallized from ethanol/isopropanol (3.5 mL:5.5 mL) to give 1.03 g (83% recovery) of an off-white powder and subsequently recrystallized from ethanol/ethyl acetate (3 mL:12 mL) to give 0.90 g (87% recovery) of a white, crystalline powder, mp 166-167° C.

1. concentrationThe resulting mixture was concentrated via rotary evaporation
2. customleaving 1.5 mL of ethanol in the solution
3. temperatureheating to near reflux, crystallization
4. temperaturethe mixture was further cooled at 5° C. for 48 h
5. filtrationThe resulting solids were filtered
6. washwashed with ethyl acetate (2×5 mL)
7. customdried at 50° C.

ORD record

ord-359b7b849900445ba34c0c0256bc2740

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08778978B2