3-Chloro-4-fluoroaniline → 2-Amino-7-chloro-6-fluorobenzothiazole

HRID 979648Notes

Reaction equation

HRID 979648 reaction equation
S1C2C3C=CC=NC=3C=CC=2C=CN1.[Cl:15][C:16]1[CH:17]=[C:18]([CH:20]=[CH:21][C:22]=1[F:23])[NH2:19].[S-:24][C:25]#[N:26].[K+].BrBr>>[NH2:26][C:25]1[S:24][C:17]2[C:16]([Cl:15])=[C:22]([F:23])[CH:21]=[CH:20][C:18]=2[N:19]=1

Participants

5

Reactant 4

HCID 97083-Chloro-4-fluoroanilineHCID 24408BromineHCID 516872Potassium thiocyanateHCID 70280881HCID 70280881, compound

Product 1

HCID 121544632-Amino-7-chloro-6-fluorobenzothiazole

Procedure

Pyrido-benzothiazine compounds having anti-microbial activity are prepared by (a) reacting 3-chloro-4-fluoroaniline with potassium thiocyanate and bromine to produce 2-amino-6-fluoro-7-chlorobenzothiazole, (b) reacting 2-amino-6-fluoro-7-chlorobenzothiazole with sodium hydroxide to produce the disulfide of 2-amino-5-fluoro 6-chlorothiophenol, (c) reacting the disulfide with sodium monochloroacetate to produce 7-fluoro-8-chloro-2H-1,4-benzothiazin-3(4H)-one, (d) reducing 7-fluoro-8-chloro-2H-1,4-benzothiazin-3(4H)-one to produce 7-fluoro-8-chloro-3,4-dihydro-2H-1,4-benzothiazone, (e) reacting 7-fluoro-8-chloro-3,4-dihydro-2-H-1,4-benzothiazone with ethyl ethoxymethylenemalonate and cyclyzing the intermediate formed with polyphosphoric acid to produce ethyl 9-fluoro-10-chloro-7-oxo-2,3-dihydro-7H-pyrido[1,2,3 de] [1,4]-benzothiazine-6-carboxylate and (f) hydrolyizing the ethyl carboxylate to produce the corresponding carboxylic acid.

Sources & evidence

ORD record
ord-646c0b753f934a879824c8faddcf50be
Source dataset
uspto-grants-1987_05
Patent number
US04668784

Reaction notes

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