Dichloromethane → N-Methyl-2-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethanamine

Temperature

88 °C

A solution of N,N-dimethyl-2-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethanamine (1.65 g, 6.17 mmol) in ClCH2CH2Cl (20 mL) was cooled to 0° C. (ice/water bath) then treated with alpha chloroethylchoroformate (1.009 mL, 9.26 mmol) dropwise. The resulting suspension was heated at 88° C. for 1.5 hours then concentrated to dryness. The residue was dissolved in MeOH (50 mL) and heated at reflux for 2 hours. The dark mixture was concentrated and partitioned between saturated sodium bicarbonate solution (50 mL) and CH2Cl2 (200 mL). The mixture was transferred to a separatory funnel and extracted. After extraction, the organic layer was separated, dried (Na2SO4), filtered, and concentrated to give a brown residue. This residue was subjected to flash chromatography on silica gel using 5:95 (2M NH3 in MeOH):CH2Cl2 as the eluent to give a yellow residue (980 mg, 62.7%). 1H-NMR (CDCl3) δ 7.97 (d, J=2.7 Hz, 1H), 7.87 (d, J=2.7, 9.3 Hz, 1H), 6.68 (d, J=9.3 Hz, 1H), 3.86-3.82 (m, 2H), 3.55 (t, J=6.6 Hz, 2H), 3.04-3.01 (m, 2H), 2.87 (t, J=6.6 Hz, 2H), 2.49 (s, 3H), 1.32 (brs, 1H).

1. concentrationthen concentrated to dryness
2. dissolutionThe residue was dissolved in MeOH (50 mL)
3. temperatureheated
4. temperatureat reflux for 2 hours
5. concentrationThe dark mixture was concentrated
6. custompartitioned between saturated sodium bicarbonate solution (50 mL) and CH2Cl2 (200 mL)
7. customThe mixture was transferred to a separatory funnel
8. extractionextracted
9. extractionAfter extraction
10. customthe organic layer was separated
11. dry with materialdried (Na2SO4)
12. filtrationfiltered
13. concentrationconcentrated
14. customto give a brown residue

ORD record

ord-63868de6fd4545dca495581036e22620

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08106043B2