Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 16066-84-5, name is tert-Butyl methylcarbamate, A new synthetic method of this compound is introduced below., Safety of tert-Butyl methylcarbamate
2-Bromo-5-hydroxy-6-nitropyridine (132.8 g, 0.606 mol), cesium carbonate (594.7 g,1.83 mol), tert-butyl methylcarbamate (116.7 g, 0.890 mol) and anhydrous DMF (4.0 L) were combined and the resultant orange mixture was sparged with nitrogen for 10 minutes. Xantphos (53.1 g, 0.0918 mol) and palladium acetate (13.5 g, 0.0601 mol) were then added and the solution was heated to 80C with continuous nitrogen gas sparging for 3 days. The mixture was allowed to cool and stir overnight. 2-Methyltetrahydrofuran (MeTHF, 4.OL) wasadded and the resultant slurry was stirred for 2.5 hours and then filtered through Celite. Thefilter cake was washed with 2 x 1.0 L of MeTHF. The filtrate was then partitioned with 8.0 Lof water. The organic layer was discarded and the aqueous layer acidified to pH 1-2 with 60mL of 12N HC1. Ethyl acetate (4.0 L) was added and the layers were separated. The organic layer was washed with water (2.0 L). The aqueous layer was back extracted with EtOAc (2 x2.0 L). The combined organic extracts were concentrated on a rotary evaporator to a brown oil. The residue was twice dissolved in EtOAc (1.0 L each time) and concentrated again. The brown oil was then dissolved in MTBE (300 mL) and loaded onto a silica gel column (SiliaFlash G-60, 3.0 L, 1.5 kg) that was pre-conditioned with 10% EtOAc/n-heptane. Thecolumn was then eluted sequentially with 10%, 20% and 30% EtOAc in n-heptane. The fractions were discarded until the eluate was yellow and then collected until cessation of color. Concentration of the combined yellow fractions on a rotary evaporator yields two crops of tert-butyl [5-hydroxy-6-nitro-2-pyridinylj(methyl)carbamate of 61.5 g and 21.3 g, (respective LC purities = 98.7% and 97.0%) with a combined yield of 82.8g (51%).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; NAVIDEA BIOPHARMACEUTICALS, INC.; CESATI, Richard R., III; CASEBIER, David S.; MORETON, Richard Christian; (49 pag.)WO2017/87965; (2017); A1;,
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