Nitrite → Propyl-(4,5,6,7-tetrahydro-benzothiazol-6-yl)-amine

HRID 1942404Notes

Reaction equation

Br.Br.[CH2:3]([NH:6][CH:7]1[CH2:16][CH2:15][C:10]2[N:11]=[C:12](N)[S:13][C:9]=2[CH2:8]1)[CH2:4][CH3:5].N([O-])=O.P(P(O)(O)=O)(O)(O)=O.[OH-].[Na+]>Cl>[CH2:3]([NH:6][CH:7]1[CH2:16][CH2:15][C:10]2[N:11]=[CH:12][S:13][C:9]=2[CH2:8]1)[CH2:4][CH3:5]

Participants

Conditions

Temperature: -30 °C

Procedure

To a solution of 14.5 g (38.9 mmol) N6-propyl-4,5,6,7-tetrahydro-benzothiazole-2,6-diamine dihydrobromide in 220 mL concentrated aqueous hydrochloric acid at −30° C. is drop wise added 66.3 mL of an aqueous 1N solution nitrite over the course of 30 minutes. After further stirring for 1 hour at the same temperature 5.44 ml (52.5 mmol) of a 50% aqueous solution hypophosphoric acid is added. The reaction mixture is stored at 4° C. overnight. After having cooled down the solution again to −30° C. the mixture is slowly basified with 40% aqueous sodium hydroxide solution while temperature is kept at −30° C. The resulting mixture is warmed up to room temperature and extracted with chloroform/ethanol 5:1 (3×250 mL). The solution is dried over anhydrous sodium sulfate and concentrated in vacuum. The brown oil obtained is chromatographically purified over silica gel, eluting with dichloromethane/methanol 97:3 under ammonia atmosphere.

Workup

customat −30° C.
customover the course of 30 minutes
additionis added
customis kept at −30° C
temperatureThe resulting mixture is warmed up to room temperature
extractionextracted with chloroform/ethanol 5:1 (3×250 mL)
dry with materialThe solution is dried over anhydrous sodium sulfate
concentrationconcentrated in vacuum
customThe brown oil obtained
customis chromatographically purified over silica gel
washeluting with dichloromethane/methanol 97:3 under ammonia atmosphere

Sources & evidence

ORD record: ord-edc6de3af82a49b6a4fe7590a5b6947a
Source dataset: uspto-grants-2013_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08389555B2

Reaction notes

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