Dibutyl squarate → 1-Butoxy-2-(3-bromopropylamino)-1-cyclobutene-3,4-dione
Reaction equation
[Br:1][CH2:2][CH2:3][CH2:4][NH2:5].[CH2:6]([O:10][C:11]1[C:14](=O)[C:13](=[O:16])[C:12]=1[O:17]CCCC)[CH2:7][CH2:8][CH3:9]>CO>[CH2:6]([O:10][C:11]1[C:12](=[O:17])[C:13](=[O:16])[C:14]=1[NH:5][CH2:4][CH2:3][CH2:2][Br:1])[CH2:7][CH2:8][CH3:9]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 22 °C
Procedure
Solid 3-bromopropylamine hydrobromide (41.52 g, 0.1897 mole) was added with stirring to a solution of sodium hydroxide (7.73 g, contains 0.187 mole) in methanol (150 mL) at 22° C., stirred for 15 minutes, then cooled to 0° C. to give a hazy solution of bromopropylamine base. The solution of bromopropylamine base was added slowly (over 20 minutes) with vigorous stirring to the product of Step A in methanol at 0° C. The mixture was stirred at 22° C. for 1.5 hours, polish filtered through diatomaceous earth (washed through with 50 mL of methanol) and added with vigorous stirring to water (1060 mL). The stirred mixture was cooled to -10° C. over several hours. The solid was collected by filtration, washed well with water (0° C., 440 mL) and dried in vacuo to give 50.0 g (91.8% yield) of the title compound as an off-white solid; m.p.=66°-68° C.
Workup
- filtrationpolish filtered through diatomaceous earth (washed through with 50 mL of methanol)
- additionadded
- stirringwith vigorous stirring to water (1060 mL)
- temperatureThe stirred mixture was cooled to -10° C. over several hours
- filtrationThe solid was collected by filtration
- washwashed well with water (0° C., 440 mL)
- customdried in vacuo
Sources & evidence
- ORD record
- ord-5ed1e9b3e6ed4aceada017765782d60e
- Source dataset
- uspto-grants-1990_05
- Patent number
- US04927970
Reaction notes
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