), 000.00 (C=O). Anal. calcd. for C~00~H~00~N~0~O~0~S (000.00): C, 00.00; H, 0.00; N, 00.00. Found: C, 00.00; H, 0.00; N, 00.00%.  *0-Acetyl-0,0-dimethyl-0-phenyl-0H-pyrazolo\[0,0-b\]pyrazine* (**00**): A mixture of 