(4-Formylthiazol-2-yl)carbamic acid tert-butyl ester

Synthesis

Step 3: tert-butyl (4-hydroxymethylthiazol-2-yl)carbamate (1.62 g, 6.95 mmol) was dissolved in 30 mL of dichloromethane. Manganese dioxide (3.65 g, 41.7 mmol) was added to this solution and the reaction mixture was stirred under reflux conditions for 2 hours. Upon completion of the reaction, the suspension was filtered through a diatomaceous earth Speed Plus pad and the filter cake was washed with dichloromethane. The filtrate was concentrated to afford the target product (4-formylthiazol-2-yl)carbamic acid tert-butyl ester as a light yellow solid (1.25 g, 78% yield). Mass spectrometry result: m/z = 229.2 ([M+H]+).

References

[1] Patent: US2007/78155, 2007, A1. Location in patent: Page/Page column 32
[2] Patent: US2006/154973, 2006, A1. Location in patent: Page/Page column 38
[3] Patent: WO2013/190508, 2013, A2. Location in patent: Page/Page column 55-56
[4] Patent: US2013/345199, 2013, A1. Location in patent: Paragraph 0579
[5] Patent: WO2016/44770, 2016, A1. Location in patent: Page/Page column 737