Methanol → 4-(5-Cyano-7-isopropylbenzo[d]oxazol-2-yl)benzoic acid

HRID 2066831Notes

Reaction equation

[C:1]([C:3]1[CH:4]=[C:5]([CH:22]([CH3:24])[CH3:23])[C:6]2[O:10][C:9]([C:11]3[CH:20]=[CH:19][C:14]([C:15]([O:17]C)=[O:16])=[CH:13][CH:12]=3)=[N:8][C:7]=2[CH:21]=1)#[N:2].O1CCCC1.CO.O.[OH-].[Li+]>O>[C:1]([C:3]1[CH:4]=[C:5]([CH:22]([CH3:24])[CH3:23])[C:6]2[O:10][C:9]([C:11]3[CH:12]=[CH:13][C:14]([C:15]([OH:17])=[O:16])=[CH:19][CH:20]=3)=[N:8][C:7]=2[CH:21]=1)#[N:2]

Participants

Conditions

Temperature: 50 °C

Procedure

To a 5-l, round-bottom flask fitted with a stir bar and a Claisen adapter fitted with a thermocouple and a nitrogen line was added was added methyl 4-(5-cyano-7-isopropyl-1,3-benzoxazol-2-yl)benzoate (40.5 g, Step B) tetrahydrofuran (1.25 l), methanol (630 ml), water (315 ml), and lithium hydroxide monohydrate (10.7 g). The mixture was heated to 50° C. and stirred at this temperature for 1 h. The mixture was then cooled and concentrated to a thick slurry. 1N HCl (3.2 l) was added and an off-white solid formed. The mixture was stirred for 5 min and then filtered, washing with water (2×500 ml). The solid was transferred to a 2-1 round-bottom flask, concentrated from toluene (1 l) and then dried in vacuo. Mass spectrum (ESI) 307.0 (M+1). 1H NMR (500 MHz, DMSO-d6): δ 8.69 (d, J=7.5 Hz, 2H), 8.28 (s, 1H), 8.16 (d, J=8.0 Hz, 2H), 7.81 (s, 1H), 3.46 (septet, J=6.5 Hz, 1H), 1.40 (d, H=7.0 Hz, 6H).

Workup

customa Claisen adapter fitted with a thermocouple
additiona nitrogen line was added
temperatureThe mixture was then cooled
concentrationconcentrated to a thick slurry
addition1N HCl (3.2 l) was added
customan off-white solid formed
stirringThe mixture was stirred for 5 min
filtrationfiltered
washwashing with water (2×500 ml)
concentrationconcentrated from toluene (1 l)
customdried in vacuo

Sources & evidence

ORD record: ord-99d729fd518442fcaa77bf49ed488809
Source dataset: uspto-grants-2012_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08293721B2

Reaction notes

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