Notes

Abstract

Notes. 34132-amino-5-methyl-Poxohexanoic acid; 2-aminomethylbenzimidazole,9 pyridoxamine,1° and P-indolylgly~ine.1~Experimental.-Condensation of ninhydrin and glycine amide. Glycine amide 12 (66 mg.) was dissolved in the minimum amount of methanol, and methanolic ninhydrin hydrate (132 mg.) was added. The mixture became dark yellow after a few minutes and was shaken at room temperature for 16 hr. The yellow crystals (46 mg.) of the condensation product (I; R = H) were separated and washed with ether and ethanol. After crystallisation from ethanol the product formed brownish yellow elongated prisms which discoloured above 275" and had m. p. 321-323" (decomp.

Alternative synthesis of 6-(3-methoxybenzyl)pyrazin-2(1H)-one. Synthesis of indeno[1,2-b]pyrazin-2-ones. Crystal structures of 5-acetoxy-1-benzyl-4-tert-butoxycarbonyl-6-(3-methoxybenzylidene)piperazin-2-one, 1-benzyl-4-tert-butoxycarbonyl-7-methoxy-1,3,4,4a-tetrahydroindeno[1,2-b]pyrazin-2-one and 1-benzyl-4-tert-butoxycarbonyl-7-methoxy-1,3,4,9-tetrahydroindeno[1,2-b]pyrazin-2-one

“…Recrystallisation from ethyl acetate-light petroleum gave pale yellow flakes, m.p. 1 19-120 "C, 1,,,(95% EtOH)/nm (log E ) 310 (3.91), 242 (4.16) and 209 (4.26); vmax(film)/cm 2978, 1695 and 1613;d,(CDCI,) 7.30 (6 H, m, ArH), 6.69 ( 1 H, d, J 2.3, ArH), 6.66 ( 1 H, dd, J2.4 and 8.2, ArH), 5.98( 1 H, d, J 1.5, C S H ) , 5.09( 1 H,m, CHN),4.97(2 H, br s, PhCH,N), 4.30 (2 H, q, J 16.6, CH,), 3.78 (3 H, s, OCH,) and 1.41 [9 H, s, C(CH,),]; m/z (CI, %) 424 (MNH,',26),407 (MH',16), 368 (IOO),351 (49),307 (68) and 91 (29) (Found: C,71.2;H,7.3;N,7.1. C24H26N204 requires C,70.9;H,7.3;N,6.9%).…”