5-[2-(2,4,6-Trifluorophenyl)-acetylamino]-pyridazine-4-carboxylic acid ethyl ester → 3-(2,4,6-trifluorophenyl)-1H-pyrido[2,3-d]pyridazine-2,4-dione

HRID 2217965Notes

Reaction equation

C(O[C:4]([C:6]1[C:11]([NH:12][C:13](=[O:24])[CH2:14][C:15]2[C:20]([F:21])=[CH:19][C:18]([F:22])=[CH:17][C:16]=2[F:23])=[CH:10][N:9]=[N:8][CH:7]=1)=[O:5])C>C1COCC1>[F:21][C:20]1[CH:19]=[C:18]([F:22])[CH:17]=[C:16]([F:23])[C:15]=1[CH:14]1[C:13](=[O:24])[NH:12][C:11]2=[CH:10][N:9]=[N:8][CH:7]=[C:6]2[C:4]1=[O:5]

Participants

Conditions

Temperature: 0 °C

Procedure

The product from Step 1 (2.5 g) was dissolved in dry THF (50 ml) and the flask purged with nitrogen. Sodium bis-trimethylsilylamide (22.1 ml of a 1M solution in THF) was added dropwise with stirring at 0° C. A yellow precipitate appeared, and the reaction was stirred for 3 hours at 0° C. The reaction was quenched with concentrated hydrochloric acid (5 ml) at 0° C. and then poured onto ice water, extracted with DCM and dried over magnesium sulphate. The solvent was evaporated to give 3-(2,4,6-trifluorophenyl)-1H-pyrido[2,3-d]pyridazine-2,4-dione as a yellow solid. Further product crystallised out of the aqueous solution overnight, to give a total yield of 1.29 g, m.p. >300° C.

Workup

customthe flask purged with nitrogen
additionSodium bis-trimethylsilylamide (22.1 ml of a 1M solution in THF) was added dropwise
stirringthe reaction was stirred for 3 hours at 0° C
customThe reaction was quenched with concentrated hydrochloric acid (5 ml) at 0° C.
additionpoured onto ice water
extractionextracted with DCM
dry with materialdried over magnesium sulphate
customThe solvent was evaporated

Sources & evidence

ORD record: ord-b3b0d8ae4e9a49758fec1fd6bdf063e1
Source dataset: uspto-grants-2008_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07410967B2

Reaction notes

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