ChemicalBook CAS DataBase List methoxyacetic anhydride

methoxyacetic anhydride synthesis

4synthesis methods

Product Name:methoxyacetic anhydride
CAS Number:19500-95-9
Molecular formula:C6H10O5
Molecular Weight:162.14

625-45-6
308 suppliers
$16.00/25g

19500-95-9
85 suppliers
$28.00/5G

Yield: 34%

Reaction Conditions:

with acetic anhydride at 100; for 2 h;

Steps:

1
6,7-Dimethoxy-1-methoxymethyl-isoquinolin-3-ol SMA 44012 A mixture of methoxyacetic acid (21.9 g, 242.67 mmol) and acetic anhydride (24.80 g, 242.67 mmol) in a 250 mL round-bottomed flask equipped with a magnetic stirrer and a distillation assembly was heated with stirring for 2 h at 100° C. and then distilled under reduced pressure. Methoxyacetic anhydride (13.5 g, 34% yield) was collected at 108° C. at around 20 mb. To a solution of methyl 2-(3,4-dimethoxy-phenyl)acetate SLA 28134 (3.36 g, 15.98 mmol) in methoxyacetic anhydride SMA 44010 (10.19 g, 62.85 mmol) at 0° C. in a 250 mL round-bottomed flask equipped with a magnetic stirrer was added dropwise HClO₄ (ca. 70% solution in water, 1.64 mL, 18.98 mmol). The mixture was then stirred for 45 min at RT then diluted with Et₂O (151 mL). The organic solution was removed to give a viscous residue that was suspended in H₂O (30 mL) at 5° C. before dropwise addition of a conc. NH₄OH solution (38 mL). After complete addition, the mixture was stirred overnight at RT and extracted with CH₂Cl₂ (50 mL) then with CH₂Cl₂:MeOH=95:5 (100 mL). The organic phase was combined, washed with brine (30 mL), dried over Na₂SO₄, filtered and concentrated at 40° C. under vacuum. Purification by column chromatography (SiO₂, eluent CH₂Cl₂:MeOH=100:0 to 93:7) gave 6,7-dimethoxy-1-methoxymethyl-isoquinolin-3-ol SMA 44012 as a yellow solid (96 mg, 2% yield). MW: 249.27; Yield: 2%; Yellow Solid. Mp (° C.): 214.1 (dec.) Rf (free base)=0.2 (CH₂Cl₂:MeOH=95:5). ¹H NMR (CDCl₃:CD₃OD=2:1, δ): 3.57 (s, 3H, OCH₃), 3.95 (s, 3H, OCH₃), 4.00 (s, 3H, OCH₃), 4.88 (s, 2H, CH₂), 6.65 (s, 1H, ArH), 6.74 (s, 1H, ArH), 6.87 (s, 1H, ArH). ¹³C-NMR (CDCl₃:CD₃OD=2:1, δ): 57.4, 57.6, 60.5, 70.3, 102.3, 104.2, 107.9, 114.5, 143.9, 145.2, 150.0, 156.9, 161.8. MS-ESI m/z (% rel. Int.): 250 ([MH]⁺, 100).