Diethyl squarate → 6-Chloro-3-(2-ethoxy-3,4-dioxo-cyclobut-1-enylamino)-2-hydroxy-N-methoxy-N-ethyl-benzenesulfonamide

HRID 516920Notes

Reaction equation

C(O[C:4]1[C:5](=[O:12])[C:6](=[O:11])[C:7]=1[O:8][CH2:9][CH3:10])C.[NH2:13][C:14]1[C:15]([OH:29])=[C:16]([S:21]([N:24]([O:27][CH3:28])[CH2:25][CH3:26])(=[O:23])=[O:22])[C:17]([Cl:20])=[CH:18][CH:19]=1>C(O)C>[Cl:20][C:17]1[C:16]([S:21]([N:24]([O:27][CH3:28])[CH2:25][CH3:26])(=[O:22])=[O:23])=[C:15]([OH:29])[C:14]([NH:13][C:4]2[C:5](=[O:12])[C:6](=[O:11])[C:7]=2[O:8][CH2:9][CH3:10])=[CH:19][CH:18]=1

Participants

Conditions

Temperature: 45 °C

Procedure

A solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (0.30 g, 1.76 mmol) in ethanol (5 ml) was treated with TEA (250 μl, 1.80 mmol) and the reaction mixture was heated to 45° C. A solution of 3-amino-6-chloro-2-hydroxy-N-methoxy-N-ethyl-benzenesulfonamide (0.58 g, 2.07 mmol) in EtOH (5 ml) was added dropwise to the reaction mixture. The reaction mixture was stirred at 45° C. for 1 hour and then concentrated in vacuo. The residue was purified using flash chromatography (50% EtOAc in iso-hexane) to furnish a solid [M+H]+ 405.2.

Workup

concentrationconcentrated in vacuo
customThe residue was purified
customto furnish a solid [M+H]+ 405.2

Sources & evidence

ORD record: ord-0b73a4c76dba492698b723bdc4800b77
Source dataset: uspto-grants-2015_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09115087B2

Reaction notes

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