Ammonia → 2-methylspiro[furo[2,3-f][1,3]benzothiazole-7,3'-indol]-2'(1'H)-one

HRID 1407560Notes

Reaction equation

HRID 1407560 reaction equation
OC[N:3]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5]([CH2:23][OH:24])([C:12]2[C:21](O)=[CH:20][C:15]3[N:16]=[C:17]([CH3:19])[S:18][C:14]=3[CH:13]=2)[C:4]1=[O:25].C(P(CCCC)CCCC)CCC.N(C(OCC)=O)=NC(OCC)=O.N.Cl>O1CCCC1>[CH3:19][C:17]1[S:18][C:14]2[CH:13]=[C:12]3[C:5]4([CH2:23][O:24][C:21]3=[CH:20][C:15]=2[N:16]=1)[C:6]1[C:11](=[CH:10][CH:9]=[CH:8][CH:7]=1)[NH:3][C:4]4=[O:25]

Participants

7

Reactant 5

HCID 222AmmoniaHCID 313Hydrochloric AcidHCID 13831TributylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 68599210HCID 68599210, compound

Product 1

HCID 461958502-methylspiro[furo[2,3-f][1,3]benzothiazole-7,3'-indol]-2'(1'H)-oneYield 71.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a cooled (−78° C.) solution of 1,3-bis(hydroxymethyl)-3-(5-hydroxy-2-methyl-1,3-benzothiazol-6-yl)-1,3-dihydro-2H-indol-2-one (1.70 g, 4.7 mmol) in anhydrous tetrahydrofuran (30 mL) was added tri-n-butylphosphine (0.80 mL, 5.7 mmol), followed by diethyl azodicarboxylate (1.05 mL, 6.7 mmol). The reaction mixture was allowed to warm to ambient temperature and was stirred for 2 h. The reaction mixture was cooled to 0° C. and a 28% aqueous solution of ammonia (10 mL) was added. The reaction mixture was stirred for 1 h at 0° C. and was acidified to pH 6 by the dropwise addition of 10% aqueous hydrochloric acid. The reaction mixture was extracted with ethyl acetate (3×50 mL) and the combined organic solution was washed with brine (2×50 mL), dried over sodium sulfate, filtered and concentrated. The resultant solid was triturated with diethyl ether (50 mL), collected by vacuum filtration, washed with diethyl ether (20 mL) and dried under high vacuum to afford 2-methylspiro[furo[2,3-f][1,3]benzothiazole-7,3′-indol]-2′(1′H)-one (1.03 g, 70%): mp>250° C. (ethyl acetate); 1H NMR (300 MHz, DMSO-d6) δ10.75 (br s, 1H), 7.89 (d, J=8.6 Hz, 1H), 7.26-7.19 (m, 1H), 7.10 (d, J=8.6 Hz, 1H), 7.02-6.86 (m, 3H), 4.86-4.74 (m, 2H), 2.60 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ 177.7, 160.1, 148.9, 141.7, 138.5, 132.7, 128.6, 128.0, 123.4, 122.7, 122.1, 119.9, 109.7, 108.3, 80.9, 57.8, 20.0; MS (ES+) m/z 309.1 (M+1).

Workup

  1. temperatureThe reaction mixture was cooled to 0° C.
  2. stirringThe reaction mixture was stirred for 1 h at 0° C.
  3. extractionThe reaction mixture was extracted with ethyl acetate (3×50 mL)
  4. washthe combined organic solution was washed with brine (2×50 mL)
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe resultant solid was triturated with diethyl ether (50 mL)
  9. filtrationcollected by vacuum filtration
  10. washwashed with diethyl ether (20 mL)
  11. customdried under high vacuum

Sources & evidence

ORD record
ord-a8f229e76c0148509d9ce9a0451b956c
Source dataset
uspto-grants-2014_12
Patent number
US08916580B2

Reaction notes

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