Hydrochloric Acid → 7-Methyl-2,3-dihydro-1,4-benzodioxine-6-carbaldehyde

Temperature

0 °C

A mixture of 6-methyl-2,3-dihydrobenzo[b][1,4]dioxine (6.4 g, 42.8 mmol) and 1,2-dichloroethane (250 mL) was cooled to 0° C. and then stirred for 1 h. After this time, dichloromethyl methyl ether (11.5 mL, 128.5 mmol) was then added and the reaction stirred for 1 h then, tin (IV) chloride (7.52 mL, 64.3 mmol) was added portion wise to the reaction over 3 h, and the reaction then allowed to warm to room temperature overnight. After this time, the reaction was poured into 3 N hydrochloric acid (150 mL) and the organic layer extracted three times with dichloromethane (100 mL). The combined organic extracts were then dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford 7-methyl-2,3-dihydrobenzo[b][1,4]dioxine-6-carbaldehyde (4.8 g, 79%) as an off-white solid; 1H NMR(500 MHz, CDCl3) δ 10.07 (s, 1H), 7.33 (s, 1H), 6.72 (s, 1H), 4.28 (m, 4H), 2.55 (s, 3H).

1. stirringthe reaction stirred for 1 h
2. customwise to the reaction over 3 h
3. customthe reaction
4. temperatureto warm to room temperature overnight
5. extractionthe organic layer extracted three times with dichloromethane (100 mL)
6. dry with materialThe combined organic extracts were then dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure

ORD record

ord-f7152c239717416183d51c6ebe9a148b

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08110681B2