Hydrochloric Acid → HCID 59853594, compound

HRID 731308Notes

Reaction equation

HRID 731308 reaction equation
[CH2:1]([O:3][C:4](=[O:19])[CH2:5][C:6]1[NH:11][C:10]2[CH:12]=[CH:13][C:14]([N+:16]([O-])=O)=[CH:15][C:9]=2[S:8][CH:7]=1)[CH3:2].[Sn](Cl)Cl.Cl>C(O)C>[CH2:1]([O:3][C:4](=[O:19])[CH2:5][C:6]1[NH:11][C:10]2[CH:12]=[CH:13][C:14]([NH2:16])=[CH:15][C:9]=2[S:8][CH:7]=1)[CH3:2]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 24479Stannous ChlorideHCID 59853577HCID 59853577, compound

Product 1

HCID 59853594HCID 59853594, compoundYield 46%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
100 °C

Procedure

A solution of (7-nitro-4H-benzo[1,4]thiazin-3-yl)-acetic acid ethyl ester (5.8 g, 20.7 mmol) in ethanol (90 mL) was treated with tin (II) chloride and 1.0 M aqueous hydrochloric acid solution (3 mL). The reaction mixture was heated at 100° C. for 3 h. The suspension was allowed to cool and was concentrated in vacuo. The crude material was suspended in ethyl acetate (90 mL) and treated with 6.0 M aqueous sodium hydroxide solution (90 mL). The resulting precipitate was filtered. The filter cake was thoroughly washed with ethyl acetate, the filtrated was washed with saturated aqueous brine solution, and concentrated in vacuo. The crude oil was purified by flash column chromatography (Merck silica gel 60, 40-63 μm, ethyl acetate/hexanes) to afford the desired product, (7-amino-4H-benzo[1,4]thiazin-3-yl)-acetic acid ethyl ester (2.38 g, 9.51 mmol, 46%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 1.21 (t, 3H, J=7.1 Hz), 3.30 (s, 2H), 3.43 (bs, 2H), 4.08 (q, 2H, J=7.1 Hz), 4.52 (s, 1H), 6.39 (dd, 1H, J1=8.3 Hz, J2=2.7 Hz), 6.46 (d, 1H, J=2.3 Hz), 6.62 (d, 1H, J=7.6 Hz), 10.38 (bs, 1H). LC-MS (ESI) calcd for C12H14N2O2S [M+H+] 251.08, found 251.23 [M+H+].

Workup

  1. temperatureto cool
  2. concentrationwas concentrated in vacuo
  3. additiontreated with 6.0 M aqueous sodium hydroxide solution (90 mL)
  4. filtrationThe resulting precipitate was filtered
  5. washThe filter cake was thoroughly washed with ethyl acetate
  6. washthe filtrated was washed with saturated aqueous brine solution
  7. concentrationconcentrated in vacuo
  8. customThe crude oil was purified by flash column chromatography (Merck silica gel 60, 40-63 μm, ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-79dfec4c3a814e779c4670707f1dee65
Source dataset
uspto-grants-2009_09
Patent number
US07582626B2

Reaction notes

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