反应详情

To a solution of (-)-α-amino-4-hydroxybenzeneacetic acid (100 g, 0.6 mole) in a minimum amount of concentrated hydrochloric acid at 35°-40° C. is added 50 ml of aqueous formaldehyde (35-37%) (0.6 mole). The addition of hydrogen chloride gas is begun. After 5-10 minutes, a solid begins to precipitate. Stirring is continued for 30 minutes, and the solid is then collected. The crude product is washed with ether and with acetone. A second crop is obtained from the filtrate after standing at room temperature overnight. Total yield is 102 g (67%) m.p. >300° C., [α]D18 =-134° (c 4.75, CH3OH) NMR (DMSO-D6) ppm (δ) 4.68 (s,2), 4.9 (broad s,1), 6.9-7.6 (superimposed q and s,3).

1. customto precipitate
2. waitis continued for 30 minutes
3. customthe solid is then collected
4. washThe crude product is washed with ether and with acetone
5. customA second crop is obtained from the filtrate
6. waitafter standing at room temperature overnight