Methanol → 3,5-Diamino-2-methylbenzoic acid

Thionyl chloride (13.0 ml, 180 mmol) was slowly added dropwise at 0° C. to a solution of 3,4-diaminobenzoic acid (25.0 g, 164 mmol) in methanol (164 ml). After stirring the mixture at room temperature overnight, it was further stirred at 80° C. overnight. The reaction mixture was cooled to room temperature, and the precipitated solid was filtered out and washed with methanol. The filtrate was concentrated under reduced pressure and the obtained solid was filtered out and washed with methanol. All of the obtained solid was dried under reduced pressure at 60° C. to obtain 3,4-diaminobenzoic acid methyl ester. The compound was identified by NMR.

1. stirringwas further stirred at 80° C. overnight
2. temperatureThe reaction mixture was cooled to room temperature
3. filtrationthe precipitated solid was filtered out
4. washwashed with methanol
5. concentrationThe filtrate was concentrated under reduced pressure
6. filtrationthe obtained solid was filtered out
7. washwashed with methanol
8. customAll of the obtained solid was dried under reduced pressure at 60° C.

ORD record

ord-86137417199741baaefb06cc9d049ea7

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07517875B2