SUMMARY ORDER
Plaintiff-appellant Gerard Corsini, an attorney proceeding pro se, appeals the district court’s judgment dismissing his complaint pursuant to 42 U.S.C. §§ 1983 and 1985. We assume the parties’ familiarity with the underlying facts, the procedural history of the case, and the issues on appeal.
We review
de novo
a district court’s decision to dismiss a complaint pursuant to Rule 12(b)(6),
see Patane v. Clark, 508
F.3d 106, 111 (2d Cir.2007), or grant judgment on the pleadings pursuant to Rule 12(c),
see Kirkendall v. Halliburton, Inc.,
Upon review, we conclude that the district court correctly dismissed Corsini’s claims that he was falsely arrested and maliciously prosecuted, and that his prosecution violated the First Amendment. Except as noted below, we affirm for substantially the reasons stated by the district court in its thorough May 15, 2014 decision.
I.Waiver
As an initial matter, we find that Corsini has waived his claims of unconstitutional search and seizure and deliberate denial of medical treatment while he was detained because his appellate brief contains no “effort at developed argumentation” with respect to those claims.
Tolbert v. Queens Coll.,
II. Conspiracy Claims
The district court’s dismissal of the conspiracy claims was appropriate. “ ‘[C]omplaints containing only conclusory, vague, or general allegations that the defendants have engaged in a conspiracy to deprive the plaintiff of his constitutional rights are properly dismissed; diffuse and expansive allegations are insufficient, unless amplified by specific instances of misconduct.’ ”
Ciambriello v. County of Nassau,
III. Res Judicata
The district court was correct that Corsini’s claims against defendants Morgan, Cary, McKay, and the law firm of Belkin Burden Wenig & Goldman, LLP, are barred by the doctrine of
res judicata,
because they are materially identical to the claims he alleged against those defendants in a state court proceeding. Corsini’s argument that the adverse state court decision does not preclude his federal claims because an appeal was pending misapprehends the application of
res judicata
under New York law. “The rule in New York,
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unlike that in other jurisdictions, is that the mere pendency of an appeal does not prevent the use of the challenged judgment as the basis of collaterally estopping a party to that judgment in a second proceeding.”
In the Matter of Amica Mut. Ins. Co.,
IV. Rule 11 Sanctions
Corsini argues that the district court abused its discretion in granting the Belkin defendants’ motion for Rule 11 sanctions, because that motion was filed with the court before the expiration of the “safe harbor” period of Rule 11(c)(2). But because the district court did not fix the amount of sanctions in its order granting the motion (and apparently has never done so), that order is not final as to the sanctions within the meaning of 28 U.S.C. § 1291.
See Pannonia Farms, Inc. v. USA Cable,
V. Leave to Amend
Finally, Corsini asserts that he should have been granted leave to amend his complaint, arguing that the district court ordinarily grants plaintiffs permission to file an amended complaint, and that it is “rare that such leave should be denied ... especially when there has been no prior amendment.” Appellant’s Br. 54. But the district court did allow Corsini to amend his complaint; he filed a first amended complaint and never formally moved to amend that complaint. Instead, he merely raised the prospect of a second amendment in his opposition to the motion to dismiss. The district court did not abuse its discretion by not addressing this vague allusion to a possible second amendment. “It is within the court’s discretion to deny leave to amend implicitly by not addressing the request when leave is requested informally in a brief filed in opposition to a motion to dismiss.”
In re Tamoxifen Citrate Antitrust Litig.,
We have considered all of Corsini’s remaining arguments and find them to be without merit. Accordingly, we AFFIRM the judgment of the district court granting the defendants’ motions to dismiss, and DISMISS that portion of the appeal challenging the sanctions order for want of jurisdiction.
