Methanol → Methyl 8-amino-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylate

HRID 724869Notes

Reaction equation

HRID 724869 reaction equation
C([NH:4][C:5]1[C:10]2[O:11][CH2:12][CH2:13][O:14][C:9]=2[C:8]([C:15]([OH:17])=[O:16])=[CH:7][CH:6]=1)(=O)C.S(=O)(=O)(O)O.[CH3:23]O>>[NH2:4][C:5]1[C:10]2[O:11][CH2:12][CH2:13][O:14][C:9]=2[C:8]([C:15]([O:17][CH3:23])=[O:16])=[CH:7][CH:6]=1

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 149562078-Acetamido-1,4-benzodioxan-5-carboxylic acid

Product 1

HCID 19711232Methyl 8-amino-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylateYield 89%

Procedure

A stirred solution of 8-acetamido-1,4-benzodioxan-5-carboxylic acid (GB 1 571 278) (2.5 g, 0.0105 mole)in methanol (60 ml) was treated with concentrated sulphuric acid (2 ml) and the solution kept at room temperature for 20 hours, then concentrated in vacuo to approxiamately 10 ml volume. The residue was treated with water (30 ml), basified with potassium carbonate and a precipitate was produced. This was filtered off, washed with water and dried to afford methyl 8-amino-1,4-benzodioxan-5-carboxylate as a white solid (1.96 g, 89%). 1H NMR (CDCl3) δ:7.38(d,1 H), 6.28(d,1 H), 4.25-4.43(m,4 H), 4.12(br s,2 H), 3.83(s,3 H).

Workup

  1. concentrationconcentrated in vacuo to approxiamately 10 ml volume
  2. additionThe residue was treated with water (30 ml)
  3. customa precipitate was produced
  4. filtrationThis was filtered off
  5. washwashed with water
  6. customdried

Sources & evidence

ORD record
ord-195af2ceab8e46768b36b30240fdf8f5
Source dataset
uspto-grants-1998_01
Patent number
US05705509

Reaction notes

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