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9th November 2011 @ 00:43
Repeat of MNR16-1:- Preparation of (S)-O,O'-1,1'-binaphthyl-2,2'-diyl bis(dimethylcarbamothioate) (MNR16-2)

MNR16-2%20scheme.png

mnr16-2.PNG

Hazard and Risk Assessment:
As for MNR15:- HIRAC MNR15

Procedure

To an ice cooled solution of (S)-1,1'-Bi(2-naphthol)(0.540 g, 1.89 mmol) in dry DMF (10 mL) under argon was added sodium hydride (60% oil dispersion) (0.19 g, 4.71 mmol). The reaction was allowed to warm to room temperature and stirred for 10 mins. N,N-dimethylthiocarbamoyl chloride (0.51 g, 4.15 mmol)was added at room temperature and the resulting mixture was heated to 85°C for 1.5 h.

The yellow-brown mixture was cooled to room temperature and poured into 1% aqueous KOH solution (30 mL) and allowed to stand over night (to try and get better precipitation) The solid was filtered and washed with water and dissolved in DCM, dried over magnsium sulfate, filtered and concentrated to give an oily gum - not like before.

Crude 0.573g

1H NMR - MNR16-2 crude - nowhere near as clean as mnr16-1

Needs further purification.

Column, 10-20% EtOAc/Hex

1H NMR frac 16-21 Product, not 100% clean

reweigh - 0.279 g, 0.61 mmol, 32 % as yellow/brown fine solid

SANY0069.JPG


Very poor yield, NaH was not washed before use, next time NaH should be washed with hexane, dried then used.

Lab book page complete, MNR
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Attached Files
mnr16-2.pdf
mnr16-2.PNG
MNR16-2 scheme.png
mnr16-2_frac8-12.pdf
SANY0069.JPG
mnr16-2_frac16-21.zip