Sodium Hydroxide → 4-(5-Chloro-2-methoxy-benzenesulfonyl)-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylic acid

HRID 1660781Notes

Reaction equation

C[O:2][C:3]([C:5]1[CH:6]=[CH:7][C:8]2[O:13][CH2:12][CH2:11][N:10]([S:14]([C:17]3[CH:22]=[C:21]([Cl:23])[CH:20]=[CH:19][C:18]=3[O:24][CH3:25])(=[O:16])=[O:15])[C:9]=2[CH:26]=1)=[O:4].[OH-].[Na+]>O1CCCC1.CO>[Cl:23][C:21]1[CH:20]=[CH:19][C:18]([O:24][CH3:25])=[C:17]([S:14]([N:10]2[C:9]3[CH:26]=[C:5]([C:3]([OH:4])=[O:2])[CH:6]=[CH:7][C:8]=3[O:13][CH2:12][CH2:11]2)(=[O:15])=[O:16])[CH:22]=1

Participants

Conditions

Temperature: 45 °C

Procedure

A solution of 4-(5-chloro-2-methoxy-benzenesulfonyl)-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylic acid methyl ester (7.1 g, 17.8 mmol) in tetrahydrofuran (100 mL) and methanol (50 mL) was treated with 3N NaOH (25 mL, 75 mmol, 4.2 equiv.). The mixture was stirred at 45° C. for 1.5 hours. The organic solvents were then removed and the residue acidified with HCl 3N (25 mL). The white precipitate which formed was filtered, washing with water, and dried under high vacuum. 4-(5-Chloro-2-methoxy-benzenesulfonyl)-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylic acid was obtained as a white solid, 6.79 g (99%), MS (ISP): m/e=382.0 (M−H), which was used crude in the following reaction.

Workup

customThe organic solvents were then removed
customThe white precipitate which formed
filtrationwas filtered
washwashing with water
customdried under high vacuum

Sources & evidence

ORD record: ord-6f75639f40064d8dac60cbaacf635c23
Source dataset: uspto-grants-2011_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08030308B2

Reaction notes

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