As a common heterocyclic compound, it belongs to benzoxazole compound, name is 4-Aminobenzo[d]oxazol-2(3H)-one, and cas is 81900-93-8, its synthesis route is as follows.
Example 28: 1-(4-chloro-2-(trifluoromethyl)benzyl)-3-(2,3-dihydro-2-oxobenzo[d]oxazol-4-yl)urea scheme 1) Preparation of 1-(4-chloro-2-(trifluoromethyl)benzyl)-3-(2,3-dihydro-2-oxobenzo[d]oxazol-4-yl)urea Commercially available 4-chloro-2-trifluoromethylbenzylamine (1 g, 4.77 mmol) was dissolved in 20ml of AcOEt and at 0C triphosgene (1.41 g, 4.77 mmol) was added to the solution. The mixture was warmed at 80C for 4 hours then evaporated and the residue was dissolved in 5 ml of DMF. The solution of the isocyanate was added dropwise to a solution in DMF (5 ml) of compound 1b (475 mg, 3.2 mmol) and the mixture was warmed at 80C for 8 hours. (TLC AcOEt 4 / petroleum ether 6). The solvent was evaporated and the crude was dissolved in AcOEt (30 ml) and washed with water (1 X 20 ml) and brine. The organic phase was dried over sodium sulfate and concentrated under vacuum. The purification of the crude residue by chromatographic column gave 120 mg of a white solid. Yield = 9.7% 1HNMR (DMSO, 200 MHz) delta 4.45 (2H, d, J = 5.6 Hz), 6.99 (4H, m), 7.65 (1H, d), 7.73 (1H, d), 7.85 (1H, bs), 8.62 (1H, bs), 11.04 (1H, bs); [M+1] 386.6 (C16H11ClF3N3O3 requires 385.73).
81900-93-8, In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles.,81900-93-8 ,4-Aminobenzo[d]oxazol-2(3H)-one, other downstream synthetic routes, hurry up and to see
Reference：
Patent; Pharmeste S.r.l.; EP2377850; (2011); A1;,
Benzoxazole – Wikipedia
Benzoxazole | C7H5NO – PubChem