Propyl p-toluenesulfonate → p-Toluenesulfonic acid
Reaction equation
[S:1]([C:8]1[CH:14]=[CH:13][C:11]([CH3:12])=[CH:10][CH:9]=1)([O:4]CCC)(=[O:3])=[O:2]>CN(C)C=O.CC(OC)(C)C>[CH3:12][C:11]1[CH:13]=[CH:14][C:8]([S:1]([OH:4])(=[O:3])=[O:2])=[CH:9][CH:10]=1Participants
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
A 72 liter unjacketed reactor was charged with 1.84 kg (10.87 mol) of R(+)-2,6 diamino-4,5,6,7-tetrahydro-benzothiazole (R(+) diamine), followed by 14.7 L of dimethyl formamide (DMF). Under continuous stirring, the mixture was heated to a temperature of between 65° C. and 68° C. A solution of 2926 grams propyl tosylate and 1761 grams diisopropylethyleamine in 3.455 L DMF was added slowly over a period of 2 hours. The reaction was continued at 67° C. for an additional 4 hours, after which the solution was gradually cooled to room temperature (18° C. to 22° C.) and stirred for an additional 15 hours. The solution was diluted with 14.72 L of MTBE over a time period of 30 minutes, and stirred for an additional 1 hour. The precipitated material was collected by filtration and washed with 7.32 L, MTBE, followed by 3 washes of 3.68 L each of ethanol, and a wash with 9.2 L heptane. The washed precipitated cake was dried under high vacuum at 30° C. to 35° C. The final weight of the dried product was 2090 grams, representing a 50% yield.
Workup
- temperatureUnder continuous stirring, the mixture was heated to a temperature of between 65° C. and 68° C
- additionwas added slowly over a period of 2 hours
- stirringstirred for an additional 1 hour
- filtrationThe precipitated material was collected by filtration
- washwashed with 7.32 L, MTBE
- washa wash with 9.2 L heptane
- customThe washed precipitated cake
- customwas dried under high vacuum at 30° C. to 35° C
Sources & evidence
- ORD record
- ord-e785ea6338194dd69e22ecc6c663d32e
- Source dataset
- uspto-grants-2013_09
- Patent number
- US08524695B2
Reaction notes
Loading…