Hydrochloric Acid → HCID 59853594, compound

HRID 730509Notes

Reaction equation

HRID 730509 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 (Example 8b, 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 concentrated. 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 brine solution, and concentrated in vacuo. The crude oil was purified by flash 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% yield) 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. concentrationconcentrated
  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 brine solution
  7. concentrationconcentrated in vacuo
  8. customThe crude oil was purified by flash chromatography (Merck silica gel 60, 40-63 μm, ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-a6feb01b3bb94a2f9ef3b478dd5a65f7
Source dataset
uspto-grants-2009_09
Patent number
US07582754B2

Reaction notes

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