Potassium Carbonate → tert-Butyl 3-oxocyclobutylcarbamate

To a vigorously stirring solution of N-Boc-3-methylene-cyclobutanamine (9.8 g, 53.5 mmol) in DCM (160 mL) and H2O (160 mL) was added K2CO3 (3 g, 21.7 mmol), followed by NaClO4 (35 g, 163.5 mmol), tetrabutylammonium chloride (0.2 g, 0.72 mmol) and RuCl3 (0.6 g, 7.6 mmol). During the course of the reaction, the organic solution turned dark brown, the catalyst turned black, while the upper aqueous layer turned white. The reaction was monitored by TLC, and upon completion, the reaction mixture was filtered through a pad of celite. The filtrates were transferred to a separatory funnel, and the aqueous layer was extracted with DCM (2×50 mL). The combined organic layers were washed with 5% NaHCO3 (2×30 mL), brine (30 mL), dried over Na2SO4, filtered and evaporated to dryness to yield a crude, which was purified by flash chromatography (silica gel/hexanes:ethyl acetate 0-60%) to yield the desired N-Boc-3-amino-cyclobutanone (7.13 g, 38.53 mmol, 72% yield): NMR (250 MHz, CDCl3) δ 4.88 (bs, 1 H), 4.13-4.29 (m, 1 H), 3.23-3.41 (m, 2 H), 2.9-3.05 (m, 2 H), 1.39 (s, 9 H).

1. customDuring the course of the reaction
2. filtrationupon completion, the reaction mixture was filtered through a pad of celite
3. customThe filtrates were transferred to a separatory funnel
4. extractionthe aqueous layer was extracted with DCM (2×50 mL)
5. washThe combined organic layers were washed with 5% NaHCO3 (2×30 mL), brine (30 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customevaporated to dryness
9. customto yield a crude, which
10. customwas purified by flash chromatography (silica gel/hexanes:ethyl acetate 0-60%)

ORD record

ord-40675c9ba0c24977ac7bc24204c11fb6

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266919B2