Sulfuric Acid → 3,3-Dioxo-1,2,3,6-tetrahydro-3lambda6-thieno[3,2-e]indole-7,8-dione

HRID 18114Notes

Reaction equation

S(=O)(=O)(O)[OH:2].[O:6]=[S:7]1(=[O:22])[CH2:11][CH2:10][C:9]2[CH:12]=[C:13]([NH:16][C:17](=[O:21])/[CH:18]=N/O)[CH:14]=[CH:15][C:8]1=2>C(OCC)(=O)C>[O:6]=[S:7]1(=[O:22])[C:8]2[C:9](=[C:12]3[C:13](=[CH:14][CH:15]=2)[NH:16][C:17](=[O:21])[C:18]3=[O:2])[CH2:10][CH2:11]1

Participants

Conditions

Temperature: 70 °C

Procedure

6.74 ml (126.38 mmol) of conc. sulphuric acid were introduced into a three-neck round-bottom flask with thermometer and high-efficiency condenser and heated to 70° C. 3.06 g (12.04 mmol) of N-(1,1-dioxo-2,3-dihydro-1H-1λ6-benzo[b]thiophen-5-yl)-2-[(E)-hydroxyimino]acetamide were then added in portions over the course of half an hour, during which the mixture became dark reddish brown in colour. After the addition was complete, the reaction mixture was heated to 90° C. and stirred at this temperature for one hour. For working up, the reaction mixture was allowed to cool to RT and was then added to a mixture of ice-water (110 ml) and ethyl acetate (25 ml) and briefly stirred. After separation of the phases, the solid which formed was filtered off with suction, washed with diethyl ether and dried in a drying oven at 50° C. overnight. 1.50 g of the desired compound were obtained.

Workup

additionAfter the addition
temperaturethe reaction mixture was heated to 90° C.
temperatureto cool to RT
stirringbriefly stirred
customAfter separation of the phases
customthe solid which formed
filtrationwas filtered off with suction
washwashed with diethyl ether
customdried in a drying oven at 50° C. overnight

Sources & evidence

ORD record: ord-fd5396e922d5440698814a38f2f2ff3b
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07741333B2

Reaction notes

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