Trifluoromethanesulfonyl chloride → Tert-butyl 6-chloro-2-methyl-spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4'-piperidine]-1'-carboxylate

HRID 1405355Notes

Reaction equation

HRID 1405355 reaction equation
[CH3:1][N:2]1[C:10]2([CH2:15][CH2:14][N:13]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:12][CH2:11]2)[C:6]2=[CH:7][CH:8]=[CH:9][N:5]2[CH2:4][CH2:3]1.FC(F)(F)S([Cl:28])(=O)=O>ClCCl>[Cl:28][C:9]1[N:5]2[CH2:4][CH2:3][N:2]([CH3:1])[C:10]3([CH2:11][CH2:12][N:13]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:14][CH2:15]3)[C:6]2=[CH:7][CH:8]=1

Participants

4

Reactant 2

HCID 79000Trifluoromethanesulfonyl chlorideHCID 68153652tert-Butyl 2'-methyl-3',4'-dihydro-2'H-spiro[piperidine-4,1'-pyrrolo[1,2-a]pyrazine]-1-carboxylate

Product 1

HCID 68153585Tert-butyl 6-chloro-2-methyl-spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4'-piperidine]-1'-carboxylateYield 77.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To tert-butyl 2-methylspiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-1′-carboxylate (5 g, 16.37 mmol) in dichloromethane (50.00 mL) at 0° C. was added trifluoromethanesulfonyl chloride (3.64 mL, 34.38 mmol) and the reaction was stirred from 0° C. to room temperature overnight. The reaction was diluted with dichloromethane and washed with water. The layers were separated and the organics were dried over sodium sulfate, filtered and concentrated. Purification of the residue by silica gel chromatography eluting with 10-100% ethylacetate in hexanes afforded tert-butyl 6-chloro-2-methyl-spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-1′-carboxylate (4.3 g, 77%), as a yellow solid. ESI-MS m/z calc. 339.2, found 340.3 (M+1)+; Retention time: 1.13 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 6.01 (d, J=3.8 Hz, 1H), 5.91 (d, J=3.7 Hz, 1H), 3.77 (t, J=6.1 Hz, 2H), 3.34 (s, 2H), 3.24 (s, 2H), 2.34 (s, 3H), 2.03 (d, J=13.1 Hz, 2H), 1.74 (t, J=11.1 Hz, 2H), 1.47 (s, 9H).

Workup

  1. washwashed with water
  2. customThe layers were separated
  3. dry with materialthe organics were dried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customPurification of the residue by silica gel chromatography
  7. washeluting with 10-100% ethylacetate in hexanes

Sources & evidence

ORD record
ord-36018379cbdc40798f57941b41a45e6f
Source dataset
uspto-grants-2014_12
Patent number
US08916565B2

Reaction notes

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