Hydrochloric Acid → HCID 15767553, compound

Participants

Reaction Steps

To a mixture of 57.8 g of a solid containing 80% of 1-(5-methylchroman-6-carbonyl)-2-t-butyl hydrazine and 20% of 1-(5-methylchroman-6-carbonyl)-1-t-butyl hydrazine and 900 ml of water was added 100 ml of concentrated hydrochloric acid at room temperature and then the the resultant was heated under reflux for 30 minutes. After cooling with ice and water, the resulting crystals were filtered to obtain 7.11 g of 5-methyl-6-chromanic acid in a yield of 16.8% (which had a purity of 99.5% by peak area from HPLC analysis and a melting point of 207° to 208° C.). An 50% aqueous solution of sodium hydroxide was added to the filtrate to pH 8 followed by extraction with dichloromethane to obtain 45.8 g of 1-(5-methylchroman-6-carbonyl)-2-t-butyl hydrazine in a yield of 79.1% (which had a purity of 99.8% by peak area from HPLC analysis and a melting point of 146° to 148° C. while which contained not more than 0.1% by peak area of 1-(5-methylchroman-6-carbonyl)-1-t-butyl hydrazine from HPLC analysis).

Provenance & Evidence