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Prepared using General Procedure 1. To 3-cyano-4-isopropoxybenzoic acid (93.2 mg, 0.45 mmol) in DMF (3 mL) was added HOBt (104.3 mg, 0.68 mmol) and EDC (130.6 mg, 0.68 mmol). The reaction was stirred at room temperature for 16 h until the acid was fully activated. (S)-N,1-dihydroxy-2,3-dihydro-1H-indene-4-carboximidamide INT-2 (97 mg, 0.5 mmol) was added in one portion and the reaction was stirred at room temperature for 2 h. The crude material was heated to 85° C. for 18 h. The reaction mixture was cooled to room temperature. Water (15 mL) was added and the mixture was allowed to stand and the dark brown precipitate was filtered. The precipitate was purified by silica gel chromatography (EA/hexane) to give 73 mg (40%) of (S)-5-(3-(1-hydroxy-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 6 as a white solid. LCMS-ESI (m/z) calculated for C21H19N3O3: 361.1. found 362.1 [M+H]+, tR=3.63 min. 1H NMR (400 MHz, CDCl3) δ 8.46 (d, J=2.1, 1H), 8.36 (dd, J=8.9, 2.2, 1H), 8.16 (dd, J=7.7, 0.5, 1H), 7.63 (d, J=7.5, 1H), 7.46 (t, J=7.6, 1H), 7.15 (d, J=9.0, 1H), 5.36 (dd, J=12.6, 6.8, 1H), 4.82 (hept, J=6.1, 1H), 3.54 (ddd, J=17.5, 8.7, 4.6, 1H), 3.31-3.18 (m, 1H), 2.63 (dddd, J=13.2, 8.4, 7.1, 4.7, 1H), 2.07 (dddd, J=14.1, 8.7, 6.6, 5.5, 1H), 1.84 (d, J=7.1, 1H), 1.50 (d, J=6.1, 6H). 13C NMR (101 MHz, DMSO) δ 173.07, 168.30, 162.46, 148.27, 142.29, 134.57, 133.77, 127.53, 127.28, 127.05, 122.26, 116.00, 115.25, 114.87, 102.43, 74.05, 72.49, 35.03, 30.80, 21.46. Chiral HPLC: (S)-5-(3-(1-hydroxy-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile was eluted with 20% IPA in hexane: >99.9% ee, tR=25.07 min. (R)-5-(3-(1-hydroxy-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 5 and racemic material were obtained in an analogous fashion from (R)-1-hydroxy-2,3-dihydro-1H-indene-4-carbonitrile and racemic 1-hydroxy-2,3-dihydro-1H-indene-4-carbonitrile respectively using General Procedure 1. tR for (R)-enantiomer=17.60 min.

1. customPrepared
2. stirringthe reaction was stirred at room temperature for 2 h
3. temperatureThe reaction mixture was cooled to room temperature
4. filtrationthe dark brown precipitate was filtered
5. customThe precipitate was purified by silica gel chromatography (EA/hexane)