bottom flask fitted with an overhead stirrer and a 500 ml addition funnel heptane 268 ml 2 u00d7 with respect 134 ml total ipa solution was added portion wise over 15 minutes after which the 22 u00b0 c mixture was cooled in an ice bath after 50 minutes the mixture was warmed to 22 u00b0 c and the thick white slurry was aged for 16 hours this was filtered and dried house vacuum n2 sweep for 5 hours affording 17 5 g of the msa salt 15 73 0 yield 99 1 purity 82 2 de 1 h nmr cd 3 2 so u03b4 9 40 d 1h 6 21 m 1h 6 09 m 1h 3 74 m 1h 2 87 m 1h 2 81 m 1h 2 31 s 3h 1 54 comp m 10h 1 04 m 1h and 0 86 ppm m 3h to a 500 erlenmeyer flask was added 17 5 g of the 5 me npr thiazalinone msa salt 15 this solid was subsequently suspended in 175 ml of dry dcm to afford a slurry sodium hydroxide 1 m 88 ml was charged to the slurry and the biphasic mixture was stirred vigorously for 16 hours after this period the biphasic mixture was transferred to a 1 l separatory funnel allowing 5 minutes for phase separation the basic aqueous layer was drained away from the organic phase after which 3 u00d7 130 ml h 2 o washes were performed on the dcm layer the ph of the final aqueous was 7 0 the dcm.