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ChemicalBook CAS DataBase List 1,3-DI-BOC-2-METHYLISOTHIOUREA
107819-90-9

1,3-DI-BOC-2-METHYLISOTHIOUREA synthesis

2synthesis methods
Di-tert-butyl dicarbonate

24424-99-5

2-Methyl-2-thiopseudourea sulfate

867-44-7

1,3-DI-BOC-2-METHYLISOTHIOUREA

107819-90-9

E) Preparation of N,N'-di-Boc-S-methylisothiourea: Di-tert-butyl dicarbonate (100 g, 458 mmol) was dissolved in tert-butanol (300 mL) under stirring conditions. Subsequently, a solution of S-methylisothiourea sulfate (32.7 g, 117 mmol) in water (150 mL) was slowly added, followed by dropwise addition of sodium hydroxide (19.2 g, 480 mmol) in water (150 mL). The reaction mixture was stirred continuously for 48 hours at room temperature. Upon completion of the reaction, the mixture was concentrated to one-third of the original volume under reduced pressure and then diluted with ether (500 mL). The organic phase was separated and washed once with water (250 mL), three times with 1N citric acid solution (250 mL), and again with water (250 mL), in that order. The organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give 42 g (62% yield) of white solid product.

-

Yield:107819-90-9 42 g (62%)

Reaction Conditions:

with sodium hydroxide;citric acid in water;tert-butyl alcohol;

Steps:

E E)

E) Preparation of N,N'-di-Boc-S-methylisothiourea To a stirring solution of di-t-butyl dicarbonate (100 g, 458 mmol) in t-butanol (300 mL) was added a solution of bis-S-methylisothiourea sulfate (32.7 g, 117 mmol) in water (150 mL), followed by a solution of sodium hydroxide (19.2 g, 480 mmol) in water (150 mL). After stirring for 48 hours, the mixture was concentrated to approximately one-third of the original volume in vacuo and diluted with diethyl ether (500 mL). The organic phase was washed once with water (250 mL), three times with 1 N citric acid (250 mL) and once again with water (250 mL). The organic phase was then dried (MgSO4), filtered and concentrated in vacuo to give 42 g (62%) of a white solid.

References:

US5914319,1999,A

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