Potassium Hydroxide → (+)-7-[1,4)Dioxan-2-yl-4-methoxy-benzothiazol-2-ylamine

HRID 985802Notes

Reaction equation

C(OC(=O)[NH:5][C:6]1[S:7][C:8]2[C:14]([CH:15]3[CH2:20][O:19][CH2:18][CH2:17][O:16]3)=[CH:13][CH:12]=[C:11]([O:21][CH3:22])[C:9]=2[N:10]=1)C.[OH-].[K+]>O1CCOCC1.C(O)CO>[O:16]1[CH2:17][CH2:18][O:19][CH2:20][CH:15]1[C:14]1[C:8]2[S:7][C:6]([NH2:5])=[N:10][C:9]=2[C:11]([O:21][CH3:22])=[CH:12][CH:13]=1

Participants

Conditions

Temperature: 100 °C

Procedure

To a stirred solution of 330 g (9.75 mmol) (+)-(7-[1,4]dioxan-2-yl-4-methoxy-benzothiazol-2-yl)-carbamic acid ethyl ester in 200 ml dioxane and 20 ml ethylene glycol was added 200 ml of a 2 N aq. potassium hydroxide solution and the mixture was heated at 100° C. for 2 days. After cooling to room temperature the mixture was poured onto water and extracted three times with ethyl acetate. The combined organic phases were washed with brine, then dried over sodium sulphate and concentrated in vacuo. Flash chromatography (1/9 acetone/dichloromethane) followed by trituration in ethyl acetate afforded 2.18 g (84 %) (+)-7-[1,4]dioxan-2-yl-4-methoxy-benzothiazol-2-ylamine as an off-white solid. [α]D20=+28.2° (c=0.92, CHCl3), ES-MS m/e (%): 267 (M+H+, 100).

Workup

temperatureAfter cooling to room temperature the mixture
additionwas poured onto water
extractionextracted three times with ethyl acetate
washThe combined organic phases were washed with brine
dry with materialdried over sodium sulphate
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-89a6db484404465eb928dd95c4e7542e
Source dataset: uspto-grants-2005_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06872833B2

Reaction notes

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