Hydrochloric Acid → HCID 57429435, compound

Temperature

0 °C

A mixture of 7-methyl-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylic acid (1.72 g, 8.8 mmol) in ethanol (100 mL) was cooled to 0° C. and stirred for 1 h prior to dropwise addition of thionyl chloride (3.9 mL, 53.2 mmol) over 1 h. After this time, the mixture was warmed to room temperature for 1 h, then transferred to an oil bath, and heated to 70° C. overnight. The mixture was then cooled to room temperature and 2 N hydrochloric acid (50 mL) added slowly followed by diethyl ether (50 mL). The aqueous layer was extracted twice with diethyl ether (50 mL), the combined organic layers washed with brine (100 mL), dried over magnesium sulfate, and concentrated under reduced pressure to afford ethyl 7-methyl-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylate (1.7 g, 89%) as a white solid: 1H NMR (500 MHz, CDCl3) δ 7.51 (s, 1H), 6.70 (s, 1H), 4.30 (q, J=7.0, 7.5 Hz, 2H), 4.26 (m, 4H), 2.49 (s, 3H), 1.36 (t, J=7.0, 7.5 Hz, 3H).

1. temperatureAfter this time, the mixture was warmed to room temperature for 1 h
2. customtransferred to an oil bath
3. temperatureheated to 70° C. overnight
4. temperatureThe mixture was then cooled to room temperature
5. extractionThe aqueous layer was extracted twice with diethyl ether (50 mL)
6. washthe combined organic layers washed with brine (100 mL)
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated under reduced pressure

ORD record

ord-f0eb801e6eb14382b49be7960e32cbf6

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08110681B2