2-Methylbenzoxazole → HCID 69817456, compound

HRID 2306536Notes

Reaction equation

[Br:1][CH2:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][C:10]([OH:12])=[O:11])=[CH:5][CH:4]=1.[CH3:13][C:14]1[O:15][C:16]2[CH:22]=[CH:21][CH:20]=[CH:19][C:17]=2[N:18]=1>ClC1C=CC=CC=1Cl>[Br-:1].[C:10]([CH2:9][C:6]1[CH:7]=[CH:8][C:3]([CH2:2][N+:18]2[C:17]3[CH:19]=[CH:20][CH:21]=[CH:22][C:16]=3[O:15][C:14]=2[CH3:13])=[CH:4][CH:5]=1)([OH:12])=[O:11]

Participants

Conditions

Temperature: 80 °C

Procedure

2-Methylbenzoxazole (yellow) was distilled under vacuum to give a colourless liquid (33 ml). 4-(Bromomethyl)phenylacetic acid (20 g, 87.3 mmol) and 2-methylbenzoxazole (distilled, 33 ml, 278 mmol) were dissolved in 1,2-dichlorobenzene (70 ml). The reaction mixture was heated at 80° C. for 2.5 days to produce a thick yellow precipitate. The reaction mixture was then cooled to room temperature, the precipitate collected via filtration and washed with 1,2-dichlorobenzene (3×100 ml) and diethyl ether (4×200 ml). The cream solid collected was dried in vacuo to give 3-(4-(carboxymethyl) benzyl]-2-methyl-1,3-benzoxazol-3-ium bromide (20 g, 55.3 mmol, 63% yield). UV (methanol): λmax=277 nm. MS: m/z=282 (C17H16NO3=282.32). Normal phase TLC (ether) indicated that the starting 2-methylbenzoxazole had an Rf=0.9±0.05 and the product an Rf=0. 1H NMR (200 MHz-DMSO-d6): δ1.75 (s, 2H); 3.2 (s, 3H); 5.85 (s, 2H); 7.31 (d, 2H, J=6.8 Hz); 7.53 (d, 2H, J=6.8 Hz); 7.72 (m, 2H, J=6.3 Hz); 7.89 (d, 1H, J=8.3 Hz); 8.17 (d, 1H, J=7.3 Hz); 9.8 (s, 1H).

Workup

customto produce a thick yellow precipitate
temperatureThe reaction mixture was then cooled to room temperature
filtrationthe precipitate collected via filtration
washwashed with 1,2-dichlorobenzene (3×100 ml) and diethyl ether (4×200 ml)
customThe cream solid collected
customwas dried in vacuo

Sources & evidence

ORD record: ord-6aa54c1915754b238d0d7a384cdc671d
Source dataset: uspto-grants-2004_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06828116B1

Reaction notes

Loading…