1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → 2-Phenylbenzo[d]oxazole-4-carboxamide

HRID 415235Notes

Reaction equation

[C:1]1([C:7]2[O:8][C:9]3[C:10](=[C:12]([C:16]([OH:18])=O)[CH:13]=[CH:14][CH:15]=3)[N:11]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C1C=CC2N(O)N=[N:25]C=2C=1.[NH4+].[Cl-].CCN(C(C)C)C(C)C.CCN=C=NCCCN(C)C>CN(C=O)C.O>[C:1]1([C:7]2[O:8][C:9]3[C:10](=[C:12]([C:16]([NH2:25])=[O:18])[CH:13]=[CH:14][CH:15]=3)[N:11]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

Conditions

Temperature: 25 °C

Procedure

To a solution of 2-phenylbenzo[d]oxazole-4-carboxylic acid in DMF (15 mL) was added HOBt (148 mg, 1.1 mmol), NH4Cl (54 mg, 1.0 mmol), DIPEA (387 mg, 3.0 mmol) and EDCI (211 mg, 1.1 mmol). The mixture was stirred at 25° C. for 10 hr. Then water (10 mL) was added and aqueous hydrochloric acid (1 N) to pH=3 and extracted with ethyl acetate (100 mL×4). The organic phase was washed with saturated sodium bicarbonate solution and brine, concentrated and dried in vacuum. The crude product was purified by pre-HPLC to obtain 2-phenylbenzo[d]oxazole-4-carboxamide as a white solid (40 mg). 1H-NMR (400 MHz, DMSO-d6) δ 7.47-7.56 (m, 1H), 7.63-7.68 (m, 3H), 7.93-8.01 (m, 3H), 8.28-8.30 (d, J=8 Hz, 2H), 8.47 (s, 1H); LC-MS (ESI) m/z 239 [M+1]+.

Workup

extractionaqueous hydrochloric acid (1 N) to pH=3 and extracted with ethyl acetate (100 mL×4)
washThe organic phase was washed with saturated sodium bicarbonate solution and brine
concentrationconcentrated
customdried in vacuum
customThe crude product was purified by pre-HPLC

Sources & evidence

ORD record: ord-735ab54c650c4917a9642fd196d03bc4
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08088760B2

Reaction notes

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