Tranilast → (E)-2-(3,4-dimethoxystyryl)-4H-benzo[d][1,3]oxazin-4-one

HRID 2175676Notes

Reaction equation

HRID 2175676 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5](/[CH:11]=[CH:12]/[C:13]([NH:15][C:16]2[CH:24]=[CH:23][CH:22]=[CH:21][C:17]=2[C:18]([OH:20])=[O:19])=O)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10]>C(OC(=O)C)(=O)C.O>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:6]=[CH:7][C:8]=1[O:9][CH3:10])/[CH:11]=[CH:12]/[C:13]1[O:19][C:18](=[O:20])[C:17]2[CH:21]=[CH:22][CH:23]=[CH:24][C:16]=2[N:15]=1

Participants

4

Reactant 1

HCID 5282230Tranilast

Product 1

HCID 10924906(E)-2-(3,4-dimethoxystyryl)-4H-benzo[d][1,3]oxazin-4-oneYield 88.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 7918Acetic AnhydrideSolvent

Procedure

A solution of (E)-2-[[3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]amino]benzoic acid (0.5 g, 1.5 mmol) in acetic anhydride (3 mL) was heated to reflux and stirred for 3 h. The reaction was cooled to rt and the resulting suspension was diluted with water. The suspension was stirred at rt for 1 h and the precipitate was collected by filtration, providing (E)-2-(3,4-dimethoxystyryl)-4H-benzo[d][1,3]oxazin-4-one (0.41 g, 88%) as a yellow crystalline solid; mp 175-179° C.; δH (500 MHz, DMSO-d6) 3.82 (s, 3H, OCH3), 3.85 (s, 3H, OCH3), 6.94 (d, J=16.0 Hz, 1H, CH═CHCO), 7.02 (d, J5′,6′=8.0 Hz, 1H, H5′), 7.35 (dd, J5′,6=8.0, J2′,6′=1.5 Hz, 1H, H6′), 7.47 (d, J2,6′=1.5 Hz, 1H, H2′), 7.58 (t, J3,4=J4,5=8.0 Hz, 1H, H4), 7.61 (d, J3,4=8.0 Hz, 1H, H3), 7.73 (d, J=16.0 Hz, 1H, CH═CHCO), 7.92 (t, J4,5=J5,6=8.0 Hz, 1H, H5), 8.12 (d, J5,6=8.0 Hz, 1H, H6); δC (125 MHz, DMSO-d6) 55.5, 55.6, 110.3, 111.6, 116.6, 122.9, 126.5, 127.4, 128.0, 128.0, 128.1, 136.8, 141.4, 146.8, 149.0, 150.9, 157.3, 158.8; HRMS (ESI) calculated for C18H15NO4 [M+H]+310.1074; found 310.1073; νmax 1020, 1254, 1515, 1634, 1755, 2835, 2940 cm−1.

Workup

  1. temperatureto reflux
  2. stirringThe suspension was stirred at rt for 1 h
  3. filtrationthe precipitate was collected by filtration

Sources & evidence

ORD record
ord-e11ff4caa4404b20978a835dbd4407d4
Source dataset
uspto-grants-2015_06
Patent number
US09062076B2

Reaction notes

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