Water → 6-Methoxy-1-methyl-1-trifluoromethylisochroman-7-carbaldehyde
Reaction equation
C1N2CN3CN(C2)CN1C3.[CH3:11][O:12][C:13]1[CH:14]=[C:15]2[C:20](=[CH:21][CH:22]=1)[C:19]([CH3:27])([C:23]([F:26])([F:25])[F:24])[O:18][CH2:17][CH2:16]2.O.[C:29]([O:33]C)(C)(C)C>FC(F)(F)C(O)=O>[CH3:11][O:12][C:13]1[CH:14]=[C:15]2[C:20](=[CH:21][C:22]=1[CH:29]=[O:33])[C:19]([CH3:27])([C:23]([F:26])([F:24])[F:25])[O:18][CH2:17][CH2:16]2Participants
Conditions
- Temperature
- 70 °C
Procedure
To hexamethylenetetramine (31.3 g, 223 mmol) was added trifluoroacetic acid (400 mL) and the mixture was heated to 70° C. for 90 minutes. A solution of 6-methoxy-1-methyl-1-trifluoromethyl-isochroman (50.0 g, 203 mmol) in trifluoroacetic acid (100 mL) was then added to the reaction mixture over 40 minutes. The solution was stirred for 3 hours and water was added (450 mL). The reaction mixture was stirred 16 hours, cooled to room temperature, and poured into methyl tert-butyl ether (500 mL). The organic layer was separated and washed with water (3×300 mL). The organic layer was poured into a round bottom flask and cooled to 0° C. 6N Sodium hydroxide was added in portions until the pH raised to 10 (˜500 mL). The organic layer was separated, washed with water (200 mL), dried over magnesium sulfate, filtered, and concentrated to afford 6-methoxy-1-methyl-1-trifluoromethyl-isochroman-7-carbaldehyde as an oil (54.2 g of a 12:1 mixture of regioisomers, 97%). 1H NMR (400 MHz, CDCl3) δ1.71 (s, 3), 2.95 (dt, 2, J=2.6, 5.3), 3.90-3.97 (m, 1), 3.97 (s, 3), 4.19 (dt, 1, J=11.2, 5.6), 6.81 (d, 1, J=1.2), 10.4 (s, 1). 13C NMR (75 MHz, CDCl3) δ23.07, 29.98, 55.73, 60.83, 76.03 (q, J=27.4), 111.81, 112.50, 123.65, 125.32, 125.64 (q, J=287), 127.06, 160.89, 188.92. IR 1683, 1616, 1498, 1296, 1271, 1163, 1149, 1120, 1096, 874 cm−1. Analysis calculated for C13H13F3O3: C, 57.13; H, 5.05. Found: C, 56.94; H, 4.78.
Workup
- stirringThe reaction mixture was stirred 16 hours
- temperaturecooled to room temperature
- customThe organic layer was separated
- washwashed with water (3×300 mL)
- additionThe organic layer was poured into a round bottom flask
- temperaturecooled to 0° C
- addition6N Sodium hydroxide was added in portions until the pH
- temperatureraised to 10 (˜500 mL)
- customThe organic layer was separated
- washwashed with water (200 mL)
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-5c799af221af4617a2d39bc720ab934e
- Source dataset
- uspto-grants-2002_11
- Patent number
- US06486325B1
Reaction notes
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