Trifluoroacetic acid → 9′-Methylspiro[piperidine-4,4′-[4H]pyrrolo[2,1-c][1,4]benzoxazine]

HRID 2204128Notes

Reaction equation

[CH3:1][C:2]1[C:3]([N:9]2[CH:13]=[CH:12][CH:11]=[CH:10]2)=[C:4]([OH:8])[CH:5]=[CH:6][CH:7]=1.O=[C:15]1[CH2:20][CH2:19][N:18](C(OC(C)(C)C)=O)[CH2:17][CH2:16]1.C(O)(C(F)(F)F)=O>ClCCl>[CH3:1][C:2]1[C:3]2[N:9]3[CH:13]=[CH:12][CH:11]=[C:10]3[C:15]3([CH2:20][CH2:19][NH:18][CH2:17][CH2:16]3)[O:8][C:4]=2[CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 25 °C

Procedure

To a solution of 3-methyl-2-(1H-pyrrol-1-yl)phenol (2.9 g, 16.6 mmol) and tert-butyl 4-oxopiperidine-1-carboxylate (3.6 g, 18.2 mmol) in dry dichloromethane (57.4 mL) was added TFA (2.5 mL, 33.1 mmol) over a 15 minutes period and the reaction was stirred at 25° C. for 12 hours. Another portion of TFA (2.5 mL, 33.1 mmol) was added at 25° C. and the reaction was stirred for 2 hours after which time a third portion of TFA (2.55 mL, 33.1 mmol) was added and the mixture was stirred at 25° C. for an additional 12 hours. The reaction mixture was diluted with CH2Cl2 (350 ml) and washed with 1M NaOH (50 ml). The organic phase was dried with MgSO4, filtered, evaporated to dryness and the resulting residue was purified by silica gel chromatography eluting with 0.5-40% MeOH in CH2Cl2 to yield 9-methylspiro[benzo[b]pyrrolo[1,2-d][1,4]oxazine-4,4′-piperidine] (2.0 g, 48%) obtained as a yellow oil. ESI-MS m/z calc. 254.1, found 255.3 (M+1)+. Retention time: 1.08 minutes (3 min run).

Workup

additionwas added
stirringthe mixture was stirred at 25° C. for an additional 12 hours
washwashed with 1M NaOH (50 ml)
dry with materialThe organic phase was dried with MgSO4
filtrationfiltered
customevaporated to dryness
customthe resulting residue was purified by silica gel chromatography
washeluting with 0.5-40% MeOH in CH2Cl2

Sources & evidence

ORD record: ord-9c3cdb2e68304b509c1115b8c911daee
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09365588B2

Reaction notes

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