Sodium Carbonate → 1-Methylcyclohexyl 2-amino-alpha-methylbenzothiazole-6-acetate

HRID 34539Notes

Reaction equation

[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([CH3:19])[C:9]([O:11][C:12]2([CH3:18])[CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]2)=[O:10])=[CH:4][CH:3]=1.[S-:20][C:21]#[N:22].[K+].BrBr.C([O-])([O-])=O.[Na+].[Na+]>C(O)(=O)C.O.C(OCC)(=O)C>[NH2:22][C:21]1[S:20][C:7]2[CH:6]=[C:5]([CH:8]([CH3:19])[C:9]([O:11][C:12]3([CH3:18])[CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]3)=[O:10])[CH:4]=[CH:3][C:2]=2[N:1]=1

Participants

Conditions

Temperature: 50 °C

Procedure

A stirred mixture of 20.9 g of 1-methylcyclohexyl 2-(p-aminophenyl)-propionate and 31.0 g of potassium thiocyanate in 150 ml of glacial acetic acid was heated in an oil bath at 50° C. and a solution of 25.6 g of Br2 in 15 ml of glacial acetic acid was added dropwise over 30 minutes. The mixture was stirred at 50° C. for an extra 30 minutes, then was cooled and poured into 1,000 ml of 3:2 water/ethyl acetate mixture. The resulting mixture was neutralized to pH 5-6 with solid Na2CO3 and filtered through celite, and the organic layer was then separated, washed with water, dried over MgSO4 and finally evaporated to dryness. Trituration of the residual oil with petroleum ether gave 18.62 g (73% yield) of 1-methylcyclohexyl 2-amino-α-methylbenzothiazole-6-acetate as creamy white crystals melting at 165°-167° C.

Workup

temperaturewas cooled
filtrationfiltered through celite
customthe organic layer was then separated
washwashed with water
dry with materialdried over MgSO4
customfinally evaporated to dryness

Sources & evidence

ORD record: ord-165c34a3852b4372953ade174c155848
Source dataset: uspto-grants-1988_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04762840

Reaction notes

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